View Full Version : Valve amps - do measurements tell it all?
Oldpinkman
11-10-2013, 10:01
Saw Bob's post on another thread and thought "you've been talking to my mate" followed by "you're gonna be in sh1t for saying it like that"
So - to move the topic to a thread of its own where it belongs, be rude about valve amplifiers here.
I would start by noting that my mate, the arch-objectivist, Mr measurement himself, and all solid state, would concede that there is more to life than measurement. Indeed - one of the reasons I have got him interested in a hifi design again is because he is fed up with designing professional equipment where measurements are all that matters.
And he commented that Quad you loved was no way to design an amp by starting with class B and all its distortions, and then correcting it.
Just a quickie to get us going :)
anthonyTD
11-10-2013, 10:11
the hilighted part i have some sympathy with, however, there are a lot of solid state and valve amplifiers out there with class B output stages that do indeed sound terrible, but a few that sound very listen able, so,[imho] its not just about the output stage configuration, and its set current draw as far as an amp being musically satisfying...
A...
Saw Bob's post on another thread and thought "you've been talking to my mate" followed by "you're gonna be in sh1t for saying it like that"
So - to move the topic to a thread of its own where it belongs, be rude about valve amplifiers here.
I would start by noting that my mate, the arch-objectivist, Mr measurement himself, and all solid state, would concede that there is more to life than measurement. Indeed - one of the reasons I have got him interested in a hifi design again is because he is fed up with designing professional equipment where measurements are all that matters.
And he commented that Quad you loved was
no way to design an amp by starting with class B and all its distortions, and then correcting it.
Just a quickie to get us going :)
cloth-ears
11-10-2013, 10:24
Saw Bob's post on another thread and thought "you've been talking to my mate" followed by "you're gonna be in sh1t for saying it like that"
So - to move the topic to a thread of its own where it belongs, be rude about valve amplifiers here.
I would start by noting that my mate, the arch-objectivist, Mr measurement himself, and all solid state, would concede that there is more to life than measurement. Indeed - one of the reasons I have got him interested in a hifi design again is because he is fed up with designing professional equipment where measurements are all that matters.
And he commented that Quad you loved was no way to design an amp by starting with class B and all its distortions, and then correcting it.
Just a quickie to get us going :)
Oh Mr Pink, you really are a diamond chap. Believe it or not it was never my intention to appear rude and I still can’t see how I was. I do agree that measurements are not everything. I have yet to meet a person who can confidently tell the difference between a distortion factor of 0.01% and 0.001%. Having said that some measurements are more important than others, I’m talking about damping factor. Valve amps, even OTL designs have a very poor damping factor. If you are driving a stiff paper cone with low loss surround then this is not as apparent as when driving a modern speakers with high loss surrounds. High loss surrounds mean that an amplifier needs to do all the work of bringing the cone back to rest (overcoming reverse current). Transistor amps are far superior at this and that is a fact that can be measured and heard.
Oldpinkman
11-10-2013, 10:34
So no issues with preamps and phono stages?
What is it with you Richard ? why don't you just take up wrestling it would keep you fit as well, far better than typing:lol:
Seriously though what do you consider an adequate damping factor I cant recall the figures at present but I have heard atmasphere valve otls that could drive a diesel locomotive
nevermind stiff paper cones (being a esl fan cant think why you would want to).
Paul
ps Bob I could not find the specs on a 606 to find a comparative amp, so no munching yet;)
Paul
Gordon Steadman
11-10-2013, 10:41
Ask any good designer and they will tell you that they can design an amp to sound good and measure well using either valves or transistors. I don't believe one is superior in principle to the other.
Having said that, I have always preferred valve amps when it comes to listening to music and reckon that anyone who prefers Trannies must be cloth eared:eyebrows:
between a distortion factor of 0.01% and 0.001%
If the 0.001% was all second harmonic and the 0.01% was all 9th and 7th, then I think you will
cloth-ears
11-10-2013, 11:00
If the 0.001% was all second harmonic and the 0.01% was all 9th and 7th, then I think you will
Nick you naughty boy. I was talking like for like and I think you know that.
Ali Tait
11-10-2013, 11:08
Difficult to get a sand and a glass amp with like for like distortion spectra methinks..
Ali Tait
11-10-2013, 11:09
Speaking for myself, I've yet to hear a solid state amp equal what the very best valve amps I've heard do.
cloth-ears
11-10-2013, 11:11
What is it with you Richard ? why don't you just take up wrestling it would keep you fit as well, far better than typing:lol:
Seriously though what do you consider an adequate damping factor I cant recall the figures at present but I have heard atmasphere valve otls that could drive a diesel locomotive
nevermind stiff paper cones (being a esl fan cant think why you would want to).
Paul
ps Bob I could not find the specs on a 606 to find a comparative amp, so no munching yet;)
Paul
Quad 606
Output, 2 X 140W 8 Ohm (both channels driven)
Maximum distortion (up to clipping point), 0.01
Output stability, Unconditionally stable into any load
Damping factor, 250
Hum and Noise, 105db
SteveTheShadow
11-10-2013, 11:16
Of course measurements matter with valve amps, just as much as they do with transistors.
Take second harmonic for example, too much of that and the thing sounds as if treacle has been poured over everything, such is the cloying sweetness. It can be attractive, but soon becomes wearing.
What you want with a valve amp is a decaying waterfall of harmonics so that the higher orders, fall away rapidly to insignificance. High order odd harmonics in particular, can give a nasty edge to the sound and must be dealt with if your valve amp is going to be any good. Triodes do this best, pentodes need feedback to sort out non linearity and reduce high output impedance so that the output stage interacts properly with a loudspeaker load. ultralinear is a half way house, giving much of the triode's lesser output impedance and sound, without the need for as much feedback as pentodes.
Single ended feed-backless valve amps are good at pulling off this harmonic waterfall trick and are capable of stunning refinement and style. Push pull amplifiers tend to cancel even harmonics and sum odd harmonics so they can be more troublesome to get right, but it is by no means impossible. Some fabulous sounding push pull triode, pentode and ultralinear amps have been manufactured in the past.
With push-pull, you get more power but at the expense of ultimate refinement. However PP will drive real world speakers far more cheaply and effectively than a single ended class A valve amp. To get equivalent power and speaker driving capability to a class A/B PP KT88, with a SE setup would need big transmitter triodes running KV of HT voltage.
For me the small trade off of refinement in favour of power, is worth it, for others SE is the only true way.
Both approaches are equally valid. BUT be very very sure, either topology with poor measured performance will
sound like crap compared to a properly designed and built amplifier.
Your valve amp won't reproduce music properly unless basic engineering principles have been used in its design and construction. After that, voicing it at valve and component level is more to do with experience and art than science, especially if you want your amp to be more than just another "me too" product.
cloth-ears
11-10-2013, 11:17
So no issues with preamps and phono stages?
My only issue with valve preamps is that I find them very temperamental. As I have now gone fully digital I only use a passive pre so not a problem.
Ali Tait
11-10-2013, 11:22
I've used a WD Pre 3 and before that a Pre 2 for many years with no issues whatsoever.
The Grand Wazoo
11-10-2013, 11:31
I've been using the same valve pre-amp for 20 years and the only problems I've had with it were caused by me messing about with it when I should have known better.
Arkless Electronics
11-10-2013, 11:42
The entire problem with valve power amps is the output transformer! OK not having "PNP" valves is rather awkward but it can be worked around....
I can design valve pre amps and phono stages with just as low distortion and wide bandwidth as solid state. It's not really an issue. Noise is lower with solid state but this only becomes a major issue if designing an MC phono stage.
OTL valve amps are never really all that successful due to the fact that valves simply aren't a low impedance device. It can work but they have to be "forced" to do that trick.
I have designed and built a power amp using valves for everything except the output devices (no drivers or anything) and it measured 0.005% THD, 1Hz - 500KHz -3dB points and damping factor of a few hundred. It's only the output transformer that prevents figures such as these from valve amps.
With the very best transformers and best topologies it is possible to achieve 0.03% THD (or there abouts), 10Hz - 50KHz and damping factor of about 30 but it is unusual to see figures such as those.
SET's ? simply not hifi. Sorry.
Oldpinkman
11-10-2013, 11:47
I'm not going to get drawn on measurements, because in spite of digging out "secrets of vacuum tube amplifiers" again for a brush up, I don't really know my arse from my elbow. Just a few thoughts to keep it warm and bubbling
Valve fans are either attracted by that "warm" , often "rolled off" sound, or by the even order harmonic sweetness - and probably enjoy the electrostatic speaker, relishing the smoothness of vocals, strings and "tonality", whereas those enjoying a bit more rough and tumble, rock fans, and even those wanting a full orchestral effect prefer good solid state when they can get it. Even die-hard valve designers don't major on "slam" or "control".
By way of extending that to professional audio - valves tend to be used in microphone preamps and the like precisely BECAUSE they colour the sound. They are used in guitar amps, where "attack" "pace" etc are not critical, but even though a guitar valve power amp is enough to fight with a PA in small venues , nobody makes a valve PA amp.
:scratch:
I only use OTL valve amps apart from lots of Quad II's which I inherited , and with the right output valve selection and a decent circuit design no trickery is involved, they are some of the simplest amplifiers around and the most stable, any of my OTL,s is quite happy powered up and unloaded for hours on end.
Paul
My only issue with valve preamps is that I find them very temperamental.
Then name and shame those "temperamental" valve preamps, I say, because there is no excuse for it - certainly it is not a problem endemic with valves. I've owned a Croft (all valve) preamp now for 8 years, which on average gets used for 5 hours each day, and have not had a single problem with it, nor indeed have I with my TD Copper amp, which gets the same amount of daily use, and which I've owned for 5 years.
Providing that a valve amplifier has been properly designed in the first place, and is used and looked after properly by its owner, it should be just as reliable/non-temperamental as any solid-state amp. Therefore, in those circumstances, the oft-mentioned "temperamental" or 'fussy'/'unreliable nature' of valve amps is a total nonsense and misnomer. Quite simply, if that's what you've experienced, then you haven't owned a decent one!! ;)
As for measurements, again a lot of bollocks is talked about. Within established and relevant parameters, all GOOD valve amplifiers should measure well. Indeed, I've yet to hear ANY amplifier valve or SS measure badly, but sound good! In my experience, the two factors are intrinsically linked. In that respect, my Croft preamp measures flat to at least 100khz, and down to a few hz at the bottom end, and I believe my TD Copper valve power amp behaves in the same way, although Anthony can of course verify this.
Of course, some solid-state amps will measure better in certain areas than a valve amp will (types of distortion), but not in any way I've found that matters to me. As for driving speakers, it's all about correct matching. Find a reasonably efficient pair of speakers, which are a 'valve friendly load' (i.e. that don't exhibit horrible dips in impedance or have overly complicated power-sucking crossovers), of which there are many examples to choose from, and you're fine!
Like Ali says (and Steve also talks much sense here), given what I've heard from truly top-notch valve amps and phono stages, I've yet to find SS ones I could live with in the long term. In comparison, most sound rather anodyne and musically un-involving.
Marco.
Valve fans are either attracted by that "warm" , often "rolled off" sound, or by the even order harmonic sweetness - and probably enjoy the electrostatic speaker, relishing the smoothness of vocals, strings and "tonality", whereas those enjoying a bit more rough and tumble, rock fans, and even those wanting a full orchestral effect prefer good solid state when they can get it. Even die-hard valve designers don't major on "slam" or "control".
Slam??
Hehehehe... I can't wait to see the look on your face when you visit and I play some Rammstein or Tool at full tilt on my system. All I'll say is make sure that you pack a clean pair of incontinence pants! :fingers: :fingers: :hairmetal: :hairmetal:
:eyebrows: :eyebrows:
Marco.
Arkless Electronics
11-10-2013, 11:56
I only use OTL valve amps apart from lots of Quad II's which I inherited , and with the right output valve selection and a decent circuit design no trickery is involved, they are some of the simplest amplifiers around and the most stable, any of my OTL,s is quite happy powered up and unloaded for hours on end.
Paul
OTL's are technically not a happy compromise. Trust me, I'm an engineer :eyebrows:
Gordon Steadman
11-10-2013, 11:58
Valve fans are either attracted by that "warm" , often "rolled off" sound, or by the even order harmonic sweetness - and probably enjoy the electrostatic speaker, relishing the smoothness of vocals, strings and "tonality", whereas those enjoying a bit more rough and tumble, rock fans, and even those wanting a full orchestral effect prefer good solid state when they can get it. Even die-hard valve designers don't major on "slam" or "control".
:scratch:
Just not true, its an old myth. The Firebottle OTL is as crisp as they come and has great 'attack' and 'slam' whatever that is. It sounds like real instruments do or at least, as close as I've heard. Tonally, my valve amps have just as much at each end of the scale as the SS amps I have had.
Gordon Steadman
11-10-2013, 11:58
OTL's are technically not a happy compromise. Trust me, I'm an engineer :eyebrows:
But they can sound terrific. Trust me, I'm a musician.
SteveTheShadow
11-10-2013, 12:00
I'm not going to get drawn on measurements, because in spite of digging out "secrets of vacuum tube amplifiers" again for a brush up, I don't really know my arse from my elbow.
Valve fans are either attracted by that "warm" , often "rolled off" sound, or by the even order harmonic sweetness - and probably enjoy the electrostatic speaker, relishing the smoothness of vocals, strings and "tonality", whereas those enjoying a bit more rough and tumble, rock fans, and even those wanting a full orchestral effect prefer good solid state when they can get it. Even die-hard valve designers don't major on "slam" or "control".
By way of extending that to professional audio - valves tend to be used in microphone preamps and the like precisely BECAUSE they colour the sound. They are used in guitar amps, where "attack" "pace" etc are not critical, but even though a guitar valve power amp is enough to fight with a PA in small venues , nobody makes a valve PA amp.
:scratch:
Whatever
Either this is a piss take or a deliberate attempt to stir things for entertainment purposes.
A worse piece of ill informed claptrap I have yet to read.
I think least said soonest mended.
Frankyc2003
11-10-2013, 12:03
Just not true, its an old myth. The Firebottle OTL is as crisp as they come and has great 'attack' and 'slam' whatever that is. It sounds like real instruments do or at least, as close as I've heard. Tonally, my valve amps have just as much at each end of the scale as the SS amps I have had.
+1, my 18 W SET fed by a top notch digital delivers 'attack', 'slam' and 'control' by bucket loads... I know it sounds weird, but it does... Nothing soft, rolled off here.
And it outperforms any SS amps I have had. Apart maybe from some of Nelson Pass masterpieces... IMHO
CAVEAT: please bear in mind that achieving amp / speakers synergy with Valve SET is essential. Not every speaker will work with SET amplifers, so tread carefully here...
Arkless Electronics
11-10-2013, 12:05
As far as reliability goes valve amps will not match solid state. That's a simple fact. The valves themselves are of course the single biggest problem.
Phono stages and pre amps will be a lot more reliable as they use lower voltages and currents and don't drive the valves hard.
I'm sure some will be champing at the bit to tell me that their Acme MkII has been reliable for 12 years or whatever... it can happen. Equally there will be some who have had nothing but trouble....
Here's a link to a technical article on my website which some may find interesting. I originally wrote it for the journal of the Institute of Sound and Communication Engineers (ISCE):
http://www.arklesselectronics.com/articles.html
It mainly mentions guitar amps etc but it's all just a s relevant to hifi amps
Arkless Electronics
11-10-2013, 12:08
But they can sound terrific. Trust me, I'm a musician.
I didn't say they couldn't sound good.... and I'm also a musician (alto sax, clarinet, guitar and bass) ;)
, I've yet to find SS ones I could live with in the long term. In comparison, most sound rather anodyne and musically un-involving.
Marco.
Probably because they have less distortion. A little bit of 2nd harmonic adds a euphonic quality to the sound. Indeed Douglas Self proposed a transistor amp wiith a 'niceness' control that allowed the user to add 2nd harmonic to taste.
You don't see this commercially because it is obviously not aspiring to high fidelity but valve amps and some transistor amps will have a little distortion that will do the job just as well, except you don't have variable adjustment.
Essentially what I am saying is that the slightly distorted sound can be more engaging to listen to but that the 'anodyne' sound is actually the more accurate rendition.
Beobloke
11-10-2013, 12:10
If the 0.001% was all second harmonic and the 0.01% was all 9th and 7th, then I think you will
Spot on. I remember a demo a few years back where two filters could be introduced to affect the music signal - one added 2% distortion and one 20%. Playing a 1kHz sine wave through the two led to the expected results - the 2% distorted one sounded bad, the 20% one sounded hideous! However, when the signal was changed to music, the 2% distorted music clip sounded awful but the 20% one sounded barely any different to normal!
The reason was that the 2% distortion was created by deliberate crossover distortion, but the 20% one was created by deliberate clipping, so any lower signals that went under the clipping level remained unaffected. Consequently, it's most definitely not only the amount of distortion you have, but the type as well.
But they can sound terrific. Trust me, I'm a musician.
Totally agree with Gordon
and as well our resident genius Firebottle , Giovanni Mariani, Ralph Karsten, and Bruce Rozenbilt to name a few designers of OTL's, manage to use that compromised topology to tremendous effect.
Paul
Arkless Electronics
11-10-2013, 12:14
Then name and shame those "temperamental" valve preamps, I say, because there is no excuse for it - certainly it is not a problem endemic with valves. I've owned a Croft (all valve) preamp now for 8 years, which on average gets used for 5 hours each day, and have not had a single problem with it, nor indeed have I with my TD Copper amp, which gets the same amount of daily use, and which I've owned for 5 years.
Providing that a valve amplifier has been properly designed in the first place, and is used and looked after properly by its owner, it should be just as reliable/non-temperamental as any solid-state amp. Therefore, in those circumstances, the oft-mentioned "temperamental" or 'fussy'/'unreliable nature' of valve amps is a total nonsense and misnomer. Quite simply, if that's what you've experienced, then you haven't owned a decent one!! ;)
As for measurements, again a lot of bollocks is talked about. Within established and relevant parameters, all GOOD valve amplifiers should measure well. Indeed, I've yet to hear ANY amplifier valve or SS measure badly, but sound good! In my experience, the two factors are intrinsically linked. In that respect, my Croft preamp measures flat to at least 100khz, and down to a few hz at the bottom end, and I believe my TD Copper valve power amp behaves in the same way, although Anthony can of course verify this.
Of course, some solid-state amps will measure better in certain areas than a valve amp will (types of distortion), but not in any way I've found that matters to me. As for driving speakers, it's all about correct matching. Find a reasonably efficient pair of speakers, which are a 'valve friendly load' (i.e. that don't exhibit horrible dips in impedance or have overly complicated power-sucking crossovers), of which there are many examples to choose from, and you're fine!
Like Ali says (and Steve also talks much sense here), given what I've heard from truly top-notch valve amps and phono stages, I've yet to find SS ones I could live with in the long term. In comparison, most sound rather anodyne and musically un-involving.
Marco.
Which is why I've decided not to send you one of my phono stages for evaluation. Sorry but I think you are biased against solid state and therefore no matter how good it is you ain't going to like it.... I will however send you a prototype valve phono stage as soon as it's ready ;)
Gordon Steadman
11-10-2013, 12:16
I didn't say they couldn't sound good.... and I'm also a musician (alto sax, clarinet, guitar and bass) ;)
I thought it was the sound that mattered or am I missing something?:scratch:
Oldpinkman
11-10-2013, 12:19
Oh no. Not the musician thing. I'm married to a professional one, and about to go an hear a bunch of professional musician friends play tonight. Most of them listen to music centres or ipods. :doh:
As far as reliability goes valve amps will not match solid state. That's a simple fact. The valves themselves are of course the single biggest problem.
Sorry, Jez, that's WAY too black and white a statement, and so it is far from being a "fact". It depends on many different factors.
Like I said, I've had my Croft valve preamp now for 8 years, which during those 8 years, has been used for 5 hours a day or more, and I've not had one single problem with it, when compared with quite a few SS designs I've owned, which have failed in some way long before then!!
As for the reliability of the valves themselves, you have a point. However, this is most noticeable with current production valves, which are nowhere near as well constructed as the best NOS varieties, and consequently are both less reliable and have a shorter lifespan.
I've had original GEC KT88s last over 15 years of constant use, and Brimar CV1988s last a similar amount of time, not to mention countless Mullard ECC83s still going strong after many, many years of daily usage, together with the amplifiers that they are/were in not exhibiting one single fault in all that time!
Therefore, it's important to refrain from making dogmatic statements, in terms of referring to issues pertaining to reliability, and retain a proper sense of balance :exactly:
Marco.
Arkless Electronics
11-10-2013, 12:26
I thought it was the sound that mattered or am I missing something?:scratch:
There are many other ways of making an amp that sounds as good or better and which involve less compromises, are smaller, cheaper and more reliable.
Ali Tait
11-10-2013, 12:27
The entire problem with valve power amps is the output transformer! OK not having "PNP" valves is rather awkward but it can be worked around....
I can design valve pre amps and phono stages with just as low distortion and wide bandwidth as solid state. It's not really an issue. Noise is lower with solid state but this only becomes a major issue if designing an MC phono stage.
OTL valve amps are never really all that successful due to the fact that valves simply aren't a low impedance device. It can work but they have to be "forced" to do that trick.
I have designed and built a power amp using valves for everything except the output devices (no drivers or anything) and it measured 0.005% THD, 1Hz - 500KHz -3dB points and damping factor of a few hundred. It's only the output transformer that prevents figures such as these from valve amps.
With the very best transformers and best topologies it is possible to achieve 0.03% THD (or there abouts), 10Hz - 50KHz and damping factor of about 30 but it is unusual to see figures such as those.
SET's ? simply not hifi. Sorry.
How about a valve amp directly coupled to an electrostatic speaker?
cloth-ears
11-10-2013, 12:28
Then name and shame those "temperamental" valve preamps, I say, because there is no excuse for it - certainly it is not a problem endemic with valves. I've owned a Croft (all valve) preamp now for 8 years, which on average gets used for 5 hours each day, and have not had a single problem with it, nor indeed have I with my TD Copper amp, which gets the same amount of daily use, and which I've owned for 5 years.
Providing that a valve amplifier has been properly designed in the first place, and is used and looked after properly by its owner, it should be just as reliable/non-temperamental as any solid-state amp. Therefore, in those circumstances, the oft-mentioned "temperamental" or 'fussy'/'unreliable nature' of valve amps is a total nonsense and misnomer. Quite simply, if that's what you've experienced, then you haven't owned a decent one!! ;)
As for measurements, again a lot of bollocks is talked about. Within established and relevant parameters, all GOOD valve amplifiers should measure well. Indeed, I've yet to hear ANY amplifier valve or SS measure badly, but sound good! In my experience, the two factors are intrinsically linked. In that respect, my Croft preamp measures flat to at least 100khz, and down to a few hz at the bottom end, and I believe my TD Copper valve power amp behaves in the same way, although Anthony can of course verify this.
Of course, some solid-state amps will measure better in certain areas than a valve amp will (types of distortion), but not in any way I've found that matters to me. As for driving speakers, it's all about correct matching. Find a reasonably efficient pair of speakers, which are a 'valve friendly load' (i.e. that don't exhibit horrible dips in impedance or have overly complicated power-sucking crossovers), of which there are many examples to choose from, and you're fine!
Like Ali says (and Steve also talks much sense here), given what I've heard from truly top-notch valve amps and phono stages, I've yet to find SS ones I could live with in the long term. In comparison, most sound rather anodyne and musically un-involving.
Marco.
Perhaps with preamps I have indeed just been unlucky as the three I have owned, Quad, Radford and Leek were all problematic for one reason or another. This is not to say that when they worked their sound was disappointing in any way and I have never said that. The problem I have with valve power amps is damping factor. Having a low damping factor limits your choice of speaker and type of music. As a specification damping factor is important yet often overlooked. The higher the damping factor the better able an amplifier is at dealing with reverse current. All moving coil speakers generate reverse currant.
Ali Tait
11-10-2013, 12:28
And how you can say SET's are simply not hi-fi is beyond me. The best amps I've heard to date have all been SET.
anthonyTD
11-10-2013, 12:29
Hi All,
I think i can speak on behalf of those that like to listen to recorded music on valve amps, and those that use valve amps to make the music, first of all,speaking about my own preferences, i do not use valves to design or build valve amps because they sound soft, or pipe and slipper sounding as some may call it,i use them first and foremost because they are very linear devices to start with, ie; they do not need feedback directly around them to linearize them individually as transistors do, secondly, i use them because in the correct circuit designs they are very immediate in their attack and response characteristics, now most guitarists [of which i have many as customers] who use valve amplifiers will tell you that those are two reasons why they continue to use valve amplifiers, now remember, these are the people [musicians] we rely on to make the music in the first place. Now, a brief mention of of the draw backs of valves, yes, they are high impedance devices, so, to couple them to a low impedance device such as a speaker, they need a step down transformer, this as many have stated is in many ways the Achilles heel of any good valve amp, especially if it has not been designed correctly. as far as OTL's are concerned, all you have to remember is; VALVES ARE HIGH IMPEDANCE DEVICES, they were not designed to drive low impedances directly, whether that be from the anode or the cathode, hence the reason a lot go pop when asked to much of them...
Now as far as distortions and the different types are concerned, another good reason for using valves in any configuration is the fact that they produce predominantly low order harmonic distortion, ie; seconds and thirds, they do not produce the higher order odd harmonics that are objectionable, even as Nick [Lurcher] stated in very small quantities...
As for valve amps not having any slam or control, well, there are many here besides me who will fight that corner...
The top and bottom of it is; both technologies have their good and bad points, and if a person is biased to one more than the other, for what ever reason, it is not hard to find things to point out in either favor or against...
Anthony,TD...
Ali Tait
11-10-2013, 12:30
Perhaps with preamps I have indeed just been unlucky as the three I have owned, Quad, Radford and Leek were all problematic for one reason or another. This is not to say that when they worked their sound was disappointing in any way and I have never said that. The problem I have with valve power amps is damping factor. Having a low damping factor limits your choice of speaker and type of music. As a specification damping factor is important yet often overlooked. The higher the damping factor the better able an amplifier is at dealing with reverse current. All moving coil speakers generate reverse currant.
Well what would you expect, using three vintage designs? Reliability will always be an issue with kit of that age, valve or SS.
Probably because they have less distortion. A little bit of 2nd harmonic adds a euphonic quality to the sound. Indeed Douglas Self proposed a transistor amp wiith a 'niceness' control that allowed the user to add 2nd harmonic to taste.
You don't see this commercially because it is obviously not aspiring to high fidelity but valve amps and some transistor amps will have a little distortion that will do the job just as well, except you don't have variable adjustment.
Essentially what I am saying is that the slightly distorted sound can be more engaging to listen to but that the 'anodyne' sound is actually the more accurate rendition.
Yes, although that has absolutely nothing whatsoever to do with what I'm referring to! ;)
There are valid reasons, in my experience, (which I'll save for another day, as I don't have time to get into it here) why most SS amps sound anodyne and 'lifeless', in comparison with the very best valve designs, and it's got nothing to do with the latter's lack of 'accuracy' (in a musical sense).
Marco.
Arkless Electronics
11-10-2013, 12:32
Sorry, Jez, that's WAY too black and white a statement, and so it is far from being a "fact". It depends on many different factors.
Like I said, I've had my Croft valve preamp now for 8 years, which during those 8 years, has been used for 5 hours a day or more, and I've not had one single problem with it, when compared with quite a few SS designs I've owned, which have failed in some way long before then!!
As for the reliability of the valves themselves, you have a point. However, this is most noticeable with current production valves, which are nowhere near as well constructed as the best NOS varieties, and consequently are both less reliable and have a shorter lifespan. I've had original GEC KT88s last over 15 years of constant use, and Brimar CV1988s last a similar amount of time, not to mention countless Mullard ECC83s still going strong after many, many years of daily usage, together with the amplifiers that they are/were in not exhibiting one single fault in all that time!
Therefore, it's important to refrain from making dogmatic statements, in terms of referring to issues pertaining to reliability, and retain a proper sense of balance :exactly:
Marco.
Simply wrong Marco. It's a scientific fact that solid state is a lot more reliable than valves. Simple as that.
Gordon Steadman
11-10-2013, 12:34
Oh no. Not the musician thing. I'm married to a professional one, and about to go an hear a bunch of professional musician friends play tonight. Most of them listen to music centres or ipods. :doh:
You know very well that I said it merely as a direct response to the previous quote. Most other musicians I know are quite happy with a Dansette.
Simply wrong Marco. It's a scientific fact that solid state is a lot more reliable than valves. Simple as that.
Not when responding to an electromagnetic pulse, they're not :)
Which is why I've decided not to send you one of my phono stages for evaluation. Sorry but I think you are biased against solid state and therefore no matter how good it is you ain't going to like it.... I will however send you a prototype valve phono stage as soon as it's ready ;)
Lol - suit yourself, Jez. However, you're completely wrong! Having owned many examples of both, I'm not biased against either. I simply judge whatever equipment it is (valve or SS) on its sonic and musical merits, in the context of my system.
I could equally say that you're running scared and don't want to send me your SS phono stage because it might be badly shown up against my current valve reference, but of course, we all know that's not true, don't we? ;)
Marco.
Simply wrong Marco. It's a scientific fact that solid state is a lot more reliable than valves. Simple as that.
Bollocks, and my personal experience (as outlined) totally disproves it, so you know where you can shove your "scientific facts"!!! :D
Marco.
Arkless Electronics
11-10-2013, 12:40
How about a valve amp directly coupled to an electrostatic speaker?
That should be the ultimate in hifi. Acoustat did if quite some time ago but it was a flawed implementation... good though.
Valves have ideal properties to do this job well. Equally there is no reason why solid state couldn't do it although valves would have the advantage at higher output levels and bigger panel sizes due to the fact that they can be obtained in higher voltage rated parts than SS. Dealing with 5000V or more has it's erm.. issues though...
Arkless Electronics
11-10-2013, 12:43
Bollocks, and my personal experience (as outlined) totally disproves it, so you know where you can shove your "scientific facts"!!! :D
Marco.
I'm a professional electronic engineer with decades of experience. I repeat that it is a fact that SS is much more reliable. Try reading up on the subject.
Sorry, I don't give a monkey's toss who you are. If my extensive personal experience contradicts your "scientific facts", then quite simply, the former is a more reliable guideline for me - end of.
"Scientific fact" or not, the UNDISPUTABLE REALITY is that the two current valve amplifiers I own have been more reliable than ANY of the multitude of SS kit I've owned in 25+ years of using hi-fi equipment.
Marco.
Arkless Electronics
11-10-2013, 12:49
Byeeeee
:scratch: :scratch:
What are you running away from?
Marco.
SteveTheShadow
11-10-2013, 13:05
Whatever
Either this is a piss take or a deliberate attempt to stir things for entertainment
Well that's entertainment I guess and NO it's not funny Mr Pink.
Arkless Electronics
11-10-2013, 13:07
:scratch: :scratch:
What are you running away from?
Marco.
As an electronic engineer, having an argument about electronics with a picture framer/art dealer is pretty pointless. Especially as you obviously know so much more about electronics than I do...
Hi Bob,
Perhaps with preamps I have indeed just been unlucky as the three I have owned, Quad, Radford and Leek were all problematic for one reason or another.
In that case, I'm not surprised. IME, vintage valve preamps, although sonically good in certain ways, are not the most reliable of things. However, update some key internal components with modern equivalents, and that situation can change rather dramatically! ;)
This is not to say that when they worked their sound was disappointing in any way and I have never said that. The problem I have with valve power amps is damping factor. Having a low damping factor limits your choice of speaker and type of music. As a specification damping factor is important yet often overlooked. The higher the damping factor the better able an amplifier is at dealing with reverse current. All moving coil speakers generate reverse currant.
You're absolutely right about damping factor. However, it depends on how that translates into real-world listening conditions, which are governed by a multitude of other factors. The thing to get right when using any valve power amplifier is to match it optimally (in an electrical sense) to the partnering speakers.
That done, experience tells me that you can play ANY type of music (often at eardrum-busting levels) without any problems whatsoever, with all the slam and control you could wish for! That's certainly the case in my system, with 95db efficient, Tannoy 15" Monitor Golds in Lockwood Major cabinets, driven by my 50W Class A valve amp - and my music collection of some 5000 CDs and records, contains everything from Rachmaninov to Rammstein!! :)
Quite simply, if my system couldn't play all types of music very well (although, as with all systems, it excels more with some music than others), then I wouldn't use any form of valve amplification.
Marco.
As an electronic engineer, having an argument about electronics with a picture framer/art dealer is pretty pointless. Especially as you obviously know so much more about electronics than I do...
Yes, but I'm not arguing about electronics, heaven forbid. You're trying to use your (undoubtedly superior) knowledge of electronics to dispute the FACTS of my personal experience!! *That* is what we're arguing about - and it's not on, muchacho :nono:
Exactly HOW does the FACT that in 25+ years of owning a multitude of amplifiers, 90% of which have been solid-state designs, the most reliable of any of them have been the two valve amps that I currently own, support your "scientific fact" that solid-state amps are more reliable??
Perhaps I've just been lucky (or unlucky, depending on how you look at it)!! :D
Of course my personal experience isn't any more 'definitive' than is, in this instance, your 'scientific facts'. However, I'm sure you'll appreciate that it's rather difficult for me to accept them as facts when they totally contradict what I've actually experienced (as indeed has Chris, TGW, with his own valve preamp). The amplifiers you've owned to date, which have been the most reliable, is not exactly something that you can 'imagine', unlike cable differences! ;)
Marco.
Oldpinkman
11-10-2013, 13:28
Tea anyone?
Funny you should say that - just made a cuppa. What have you started? And somehow shifted the blame onto me...:scratch:
Beobloke
11-10-2013, 13:30
And how you can say SET's are simply not hi-fi is beyond me. The best amps I've heard to date have all been SET.
Regardless of sound, the DIN 45500 specification for what constitutes "high fidelity" requires an amplifier to have an output of 10 Watts if mono, or 6W per channel if stereo. This means that quite a few SETs fall at the first hurdle!
Gordon Steadman
11-10-2013, 13:32
Funny you should say that - just made a cuppa. What have you started? And somehow shifted the blame onto me...:scratch:
'Cos ultimately, everything is your fault. Just have to live with it:lol:
By the way, tea is no solution to anything, dreadful muck. What you need is a nice cup of black sweet elixir.
Funny you should say that - just made a cuppa. What have you started? And somehow shifted the blame onto me...:scratch:
Started nowt on this thread.
Nope - it's all Pinky's fault!! :lolsign:
Marco.
anthonyTD
11-10-2013, 14:10
Afew points i would like to add to my earlier post below, first of all, concerning the reliability of either technology, valves unfortunately wear out, its the nature of how they are designed and work, ie; there is only a set amount of cathode material present in any valve to produce the emission of electrons needed for the valve to work,also, over time, valve internals become prone to shorts due mainly to the heat involved, and the movement of the structures within. Now, solid state devices don't work on the same principle, so in theory, do not wear out as far as emission is concerned, however, they do suffer from cyclic thermal breakdown, which can in time lead to failier, ie; internal shorts etc, now' modern technology as far as circuit components have' as a whole extended the life of both technologies over the years, and quite considerably in some cases.so' it can be argued that by taking both types of device topologies in modern context, one can be as reliable as the other, taking into account that valves will eventually need changing due to their emission characteristics, and solid state devices will in some cases need to be changed due to their cyclic breakdown issues...Just trying to be fair to both technologies here...
A...
Hi All,
I think i can speak on behalf of those that like to listen to recorded music on valve amps, and those that use valve amps to make the music, first of all,speaking about my own preferences, i do not use valves to design or build valve amps because they sound soft, or pipe and slipper sounding as some may call it,i use them first and foremost because they are very linear devices to start with, ie; they do not need feedback directly around them to linearize them individually as transistors do, secondly, i use them because in the correct circuit designs they are very immediate in their attack and response characteristics, now most guitarists [of which i have many as customers] who use valve amplifiers will tell you that those are two reasons why they continue to use valve amplifiers, now remember, these are the people [musicians] we rely on to make the music in the first place. Now, a brief mention of of the draw backs of valves, yes, they are high impedance devices, so, to couple them to a low impedance device such as a speaker, they need a step down transformer, this as many have stated is in many ways the Achilles heel of any good valve amp, especially if it has not been designed correctly. as far as OTL's are concerned, all you have to remember is; VALVES ARE HIGH IMPEDANCE DEVICES, they were not designed to drive low impedances directly, whether that be from the anode or the cathode, hence the reason a lot go pop when asked to much of them...
Now as far as distortions and the different types are concerned, another good reason for using valves in any configuration is the fact that they produce predominantly low order harmonic distortion, ie; seconds and thirds, they do not produce the higher order odd harmonics that are objectionable, even as Nick [Lurcher] stated in very small quantities...
As for valve amps not having any slam or control, well, there are many here besides me who will fight that corner...
The top and bottom of it is; both technologies have their good and bad points, and if a person is biased to one more than the other, for what ever reason, it is not hard to find things to point out in either favor or against...
Anthony,TD...
The Grand Wazoo
11-10-2013, 14:20
Trying to bring a little perspective into this, I think Marco and Mr Arkless are at cross purposes because Marco, as do I, regards a valve in an amp as a consumable item. Hopefully, Marco agrees with me there! Therefore we accept that a valve is liable to fail and, as such, is to a degree, unreliable. But if you appreciate they are a consumable item, and plan for them to be changed at appropriate intervals, then the device in which they are used is unlikely to be more unreliable than any other.
Is my car unreliable because I have a flat tyre every now and then? No - I take appropriate measures to deal with that, should it happen and try my best to keep an eye on the condition of the tyres I use. This is precisely the same situation.
If Mr Arkless had said "valves are more unreliable than transistors", then I couldn't disagree. But, are valve amps more unreliable than transistor amps? Aside from the timely replacement of consumables, no, not in my experience. But my experience is not yours or anyone else's.
And I own, and have used both valve and transistor power amplifiers for decades.
EDIT: Anthony was obviously thinking about consumables as I was!
Afew points i would like to add to my earlier post below, first of all, concerning the reliability of either technology, valves unfortunately wear out, its the nature of how they are designed and work, ie; there is only a set amount of cathode material present in any valve to produce the emission of electrons needed for the valve to work,also, over time, valve internals become prone to shorts due mainly to the heat involved, and the movement of the structures within. Now, solid state devices don't work on the same principle, so in theory, do not wear out as far as emission is concerned, however, they do suffer from cyclic thermal breakdown, which can in time lead to failier, ie; internal shorts etc, now' modern technology as far as circuit components have' as a whole extended the life of both technologies over the years, and quite considerably in some cases.so' it can be argued that by taking both types of device topologies in modern context, one can be as reliable as the other, taking into account that valves will eventually need changing due to their emission characteristics, and solid state devices will in some cases need to be changed due to their cyclic breakdown issues...Just trying to be fair to both technologies here...
Indeed... It's important that Jez's rather dogmatic (understandably commercially biased) outburst is put into proper perspective.
Furthermore, on the subject of facts, here's a REAL one:
The FACT is, if it were genuinely a scientific fact that solid-state amps are more reliable than valve ones, then it would have been an impossibility that the two most reliable amplifiers I've owned to date have been valve-based.
Given that I was there when the SS amps in question, I've owned, failed after time (in various different ways), and I've also been here when my current valve preamp and power amp haven't failed, within a timescale far greater than that, then unless I've somehow dreamt it all, quite clearly said 'scientific fact' is anything but that.....
I contend, therefore (as you've outlined), that modern day valve amplifiers, vacuum tubes themselves aside, can be made to be just as reliable as any solid-state amplifers - indeed my experience of owning both proves just that :)
Marco.
Trying to bring a little perspective into this, I think Marco and Mr Arkless are at cross purposes because Marco, as do I, regards a valve in an amp as a consumable item. Hopefully, Marco agrees with me there! Therefore we accept that a valve is liable to fail and, as such, is to a degree, unreliable. But if you appreciate they are a consumable item, and plan for them to be changed at appropriate intervals, then the device in which they are used is unlikely to be more unreliable than any other.
Is my car unreliable because I have a flat tyre every now and then? No - I take appropriate measures to deal with that, should it happen and try my best to keep an eye on the condition of the tyres I use. This is precisely the same situation.
If Mr Arkless had said "valves are more unreliable than resistors", then I couldn't disagree. But, are valve amps more unreliable than transistor amps? Aside from the timely replacement of consumables, no, not in my experience. But my experience is not yours or anyone else's.
And I have, and have used both valve and transistor power amplifiers for decades.
SPOT ON, Chris... *That* is exactly the point!!! :clap:
Marco.
Firebottle
11-10-2013, 14:25
I'm enjoying this thread, it's better with a Jenlain than a cup of tea, don't drink the stuff myself.
Marco, stop getting on you high horse :rolleyes:, I don't think anyone is disputing the fact that your own experience has shown that the valve kit you have is reliable.
Just give Jez and the professional engineers on here some slack to express their lifetime experience with multitude different bits of kit. Some of it probably thrashed to within a mm of its life :mental:
:cool: Alan
cloth-ears
11-10-2013, 14:35
Nope - it's all Pinky's fault!! :lolsign:
Marco.
No it’s all my fault. Please pour your bile on me and spare the others. For it was I who uttered the “valve” word in the first place. If it’s to be a duel at dawn then bring your rusty muskets and I shall bring my 50 cal Gatling gun. Meet me on Hampstead Heath at dawn.
hifi_dave
11-10-2013, 14:36
Indeed... It's important that Jez's rather dogmatic (understandably commercially biased) outburst is put into proper perspective.
Furthermore, on the subject of facts, here's a REAL one:
The FACT is, if it were genuinely a scientific fact that solid-state amps are more reliable than valve ones, then it would have been an impossibility that the two most reliable amplifiers I've owned to date have been valve-based.
Given that I was there when the SS amps in question, I've owned, failed after time (in various different ways), and I've also been here when my current valve preamp and power amp haven't failed, within a timescale far greater than that, then unless I've somehow dreamt it all, quite clearly said 'scientific fact' is anything but that.....
I contend, therefore (as you've outlined), that modern day valve amplifiers, vacuum tubes themselves aside, can be made to be just as reliable as any solid-state amplifers - indeed my experience of owning both proves just that :)
Marco.
I've been selling valve amps for 40 years and the number of faulty units is miniscule to the numbers sold and the 'faults' were almost exclusively valve related. It's probably because I am picky and have stuck with brands that design and build properly, so they are inherently more reliable.
In that same time I have sold many transistor amps and some of those brands have produced very unreliable products, so much so that I have had to drop them from my stock.
Hi Alan,
Marco, stop getting on you high horse :rolleyes:, I don't think anyone is disputing the fact that your own experience has shown that the valve kit you have is reliable.
Well, I only 'get on my high horse', as you put it, when someone tries to tell me that what I've genuinely experienced is 'wrong'.
What you're claiming not to have happened, actually did on post #42, when after outlining my own genuine experience of using both valve and SS amps, Jez rather dogmatically told me that I was "simply wrong", see here: http://theartofsound.net/forum/showthread.php?28404-Valve-amps-do-measurements-tell-it-all&p=489639#post489639
If instead he'd stated it is was a scientific fact that transistors last longer than valves, but accepted that my experience of using both types of amplification was valid, where I'd found the best valve amps (as devices in general) more reliable, then I wouldn't have 'gotten on my high horse' Simples!! ;)
Anyway, glad you're enjoying the thread. I may be also sipping some Jenlain later! :cool:
Marco.
I've been selling valve amps for 40 years and the number of faulty units is miniscule to the numbers sold and the 'faults' were almost exclusively valve related. It's probably because I am picky and have stuck with brands that design and build properly, so they are inherently more reliable.
In that same time I have sold many transistor amps and some of those brands have produced very unreliable products, so much so that I have had to drop them from my stock.
Nice one, Dave. That's another FACT worth considering in the reliability stakes.....
Let's face it, in a point-to-point hard-wired (line only) valve preamp, compared with the sheer mass of components inside many line-only (active) high-end SS preamps today, there's not exactly much to go wrong!! ;)
Marco.
anthonyTD
11-10-2013, 14:56
In silicon power transistor applications, thermal cycling of the transistor may activate a failure mechanism called thermal fatigue. This phenomenon is caused by the mechanical stresses set up by the differential in the thermal expansions of the various materials used in the assembly and heat sink of the transistor.Thermal fatigue often results in cracking of the silicon pellet or failure at the silicon mounting interface.
Fact...
A...
Arkless Electronics
11-10-2013, 15:05
I stick by everything I said 100%
I work on both valve and solid state amps, pro and consumer, everyday. I design and build both types also. Did anyone actually read the article on my site I linked to?
Obviously it's the valves themselves that cause valve amps to be less reliable!! Especially output valves! More especially modern output valves!
Arkless Electronics
11-10-2013, 15:08
In silicon power transistor applications, thermal cycling of the transistor may activate a failure mechanism called thermal fatigue. This phenomenon is caused by the mechanical stresses set up by the differential in the thermal expansions of the various materials used in the assembly and heat sink of the transistor.Thermal fatigue often results in cracking of the silicon pellet or failure at the silicon mounting interface.
Fact...
A...
Also electro-migration within some solid state devices. But around 100+ valves will fail for every transistor that suffers this problem!
Oldpinkman
11-10-2013, 15:16
I'm a bit wary of poking my head over the parapet, but probably the reliability thing is a bit of a distraction.
Jez is - as an engineer - quite correctly referring to the general case, rather than the "Marco's bedroom" case - important though that may be on this forum
And Marco is right in saying what he experiences is just that, and nobody knows better about it than him.
I think the whole thing misses the point a bit. Valves burn out, and as Chris said have to be replaced like an oil change from time to time. But the term "unreliable" is being hyperboled in true AOS style, to mean "lucky to make it to the end of the record" - and nobody means that.
Much more fun to stick to talking about why SS sounds so much better than valves. (It's alright Alan - it's still safe to send me your amp to try. I'm not anti-valve by a long way. I have a valve headphone amp I'm playing with, and my precious valve guitar amp, and I'll swap you a Pip so you can judge for yourself regardless of whether I like it or not).
I am distressingly out of Jenlain, but will be out tonight anyway listening to live blues music, played by my mate Joe Gibson, on his much loved VALVE amplifier (Dr Z EZG 50)- check him and the band out. They won a national blues band competition since I last posted about them, and as a prize flew to New Brunswick Canada to win a blues festival there too. Joe is the guy at the front on my avatar.
http://www.davidmigdenandthedirtywords.com/joe-gibson
I'd still try to get a vinyl pressing of the bands album if I can rustle a bit of support. Chant after me "WE WANT A VINYL LP"
Does anyone here listen to blues????
Laters :cool:
I stick by everything I said 100%
I work on both valve and solid state amps, pro and consumer, everyday. I design and build both types also. Did anyone actually read the article on my site I linked to?
Obviously it's the valves themselves that cause valve amps to be less reliable!! Especially output valves! More especially modern output valves!
I'm afraid you didn't make that clear. And just as Chris has said, if you make allowances for the fact that the valves will 'go pop' sometime, then where's the issue?
Quite simply, the rest of the design of a valve amplifier, tubes aside, is no more less reliable than that of an SS device, in fact in some cases a hard-wired line-only valve amp is probably MORE reliable, due to the existence of less active components, which explains not only my experiences, but also those of Chris and Dave.
Furthermore, I got more than 15 years of continual usage in my amp out of GEC KT88 output valves, so where does that fit in with your argument that output valves aren't reliable, and how does that timescale compare with the lifespan of your average transistor?
I'll let you know how long my current (modern production) Tung Sol KT120s last. After 18 months of continual use for 5-8 hours a day, there's still going strong.... ;)
Marco.
Yes Richard i listen to the blues and play in a blues band and use a Fender Deville amp the only issue i had with it after 8 years continuous gigging was a valve go down replaced it sorted, And yes we all use valve amps nether had a problem apart from the odd valve going down and the amps take some stick.
The Grand Wazoo
11-10-2013, 15:27
There's this perspective thing again, in that from the user's point of view, the valves can be easily swapped and replaced, and many people do that almost as soon as they buy some valve gear. So from their perspective, they are almost an adjunct to the design.
Conversely, to the engineer who designed and built the thing, the valves are a vital and inherent part of the whole but then he has a completely different relationship with the product. The reliability of the valves is much more likely to be taken into account by him than by the tweak obsessed git who buys it (present company excepted!)
So gents, I'd suggest that you're both looking down the same telescope, but from different ends.
Oldpinkman
11-10-2013, 15:31
Yes Richard i listen to the blues and play in a blues band and use a Fender Deville amp the only issue i had with it after 8 years continuous gigging was a valve go down replaced it sorted, And yes well use valve amps nether had a problem apart from the odd valve going down and the amps take some stick.
Great. I'll start another thread someday soon, but I am looking to find enough people who like blues, and like that band, for me to get a limited vinyl run produced. Whilst I'm allowed to drift on my own thread, I rather think my attempts to plug Joe and his band are being lost in cannon smoke from the valve discussion
Ah me :rolleyes:
Jez is - as an engineer - quite correctly referring to the general case, rather than the "Marco's bedroom" case - important though that may be on this forum
And Marco is right in saying what he experiences is just that, and nobody knows better about it than him.
It's not only with my system at home where I've formed my experiences with valves and SS designs, but also in many other systems over the years and also when I was in the trade, working at various hi-fi retailers, so I have amassed considerable experience in this area. Your last sentence is spot on and indeed applies to everyone else, not just to me.
However, it always gets my back up when my genuine experiences are being rather rudely dismissed as 'wrong', simply because they don't fit with some so-called 'scientific facts'.
I think the whole thing misses the point a bit. Valves burn out, and as Chris said have to be replaced like an oil change from time to time. But the term "unreliable" is being hyperboled in true AOS style, to mean "lucky to make it to the end of the record" - and nobody means that.
Well, that's not how I was interpreting it. No-one would've disputed the fact that transistors are more reliable than valves, but that's not what Jez appeared to be saying, which was that valve amplifiers, as a complete entity, were less reliable than SS amps, as a complete entity, which has been proven from people's genuine experiences to the contrary, not to automatically be the case.
Much more fun to stick to talking about why SS sounds so much better than valves...
Lol - aye, in your opinion so far. Bring whichever SS amp you want up with you when you visit and we'll see if you leave holding the same opinion! :eyebrows: ;)
Marco.
Oldpinkman
11-10-2013, 15:34
No it’s all my fault. Please pour your bile on me and spare the others. For it was I who uttered the “valve” word in the first place. If it’s to be a duel at dawn then bring your rusty muskets and I shall bring my 50 cal Gatling gun. Meet me on Hampstead Heath at dawn.
Thanks Bob. You're right of course, but I'm so used to being on the naughty step it feels like home. They've got one with my name on now :lol:
The Grand Wazoo
11-10-2013, 15:36
I think one or two people are struggling with the extrapolation of your own personal experience into a 'universal truth' Marco.
Cheers guys what an excellent day this has been on here,but must admit i got nothing done at work today :rolleyes: so my boss will probly winge at me but hey its been interesting reading loved it brilliant site :D
SteveTheShadow
11-10-2013, 15:50
Don't get me started on the MF A1 amp I had in 1985.
you could blow the output stage simply by turning the amp on.
I went through three before I got my money back from the dealer.
at first they said it had to be my speakers or the cable at fault.
KEF Coda IIIs and QED 79 strand was not a nasty combination.
When they switched the shop demo model on and it blew its left channel
output stage, they finally began to take notice.
OK so this anecdotal evidence proves nothing, except that transistors too can be problematic, given the right conditions. But Arkless does have a point, he does know what he is on about.
I'll tell you what does rankle with me. It is the fact that due deference is no longer given to people who know know their stuff inside out and backwards.
Example, I teach primary age children, and everyone and his uncle reckons they know better than me and think I ought to be held accountable for this that and the other, same with nurses, doctors, firefighters, police and just about every profession where the layman thinks he can stick his oar in.
Makes me wonder where it is all going to end. Made me laugh to hear that at least two of Gove's free schools have been forced to close because their management teams made such a balls up. A Head with no teaching qualification was forced to resign from another one of these places because she couldn't handle the workload.
What has this to do with whether valves are less reliable than transistors?
Well it is symptomatic of a widespread attitude problem from people with only some knowledge, thinking that they know everything.
You see it every day, from the factory floor to the boardroom. I've been in meetings with such people and lost the will to live. The trouble is, these know-it-alls are type A go-getter personalities with power out of proportion to their abilities and use this attribute without mercy, to drive a coach and horses through anything and anyone who dares to use common sense.
I learned to build valve amps by reading Morgan Jones, Radiotron Designer's handbook, listening to people who had the knowledge and learning from them. I deferred to their greater expertise and guess what, they knew what they were talking about, my amps began to sound bloody good and the more advice I took on board the better the amps got.
Engineers IME by and large are a taciturn bunch, not loud and aggressive individuals. They work damned hard to get where they are and are understandably miffed when their expertise is mocked.
I have nothing but respect for those people, who with their freely given advice and expertise have brought me to the stage where I can design and create something that brings the wonders of recorded music into my living room. compared to them, what I know about valve amps wouldn't fit on a pinhead, so I respect their right to advise.
Bombast, fury and the "I know everything about everything so bollocks to you" type attitude will reduce this world to rubble in the end.
anthonyTD
11-10-2013, 15:59
Modern Valves are quite poor in construction and material content in comparison to most New old stock versions,
However, as others here have said, including musicians, [who's gear really do test valves to their limit as far as physical abuse is concerned] they are still relatively reliable in terms of their usage within their normal parameters, when either device fails there are associated components that can and often do fail in conjunction, in valve amplifiers sporting output transformers its usually a case of plate load and or screen grid resistors that fail,
With no potential of high voltage reaching anything connected to it, however, in conventional transistor based designs it is of great importance to employ additional circuitry for protection in the event of a device going bad, in most cases, this would be in the form of a thermal protection switch mounted to the output devices themselves, or their heat sinks,which in turn will switch off the unit when the temperature of the devices reach a state of temperature which is deemed unacceptable etc, and or a DC detection circuit, which will' [hopefully] in the event of a device failing, also shut down the unit or its output stage, this can be the only sure way of protecting any speaker unit connected, most modern well designed solid state amps employ either one or both, which is very re-assuring, especially if you are using a very cherished or expensive pair of speakers...
A...
wee tee cee
11-10-2013, 16:03
fine post steve, as Billy Connolly said, "experts in fuck all!".......ah.. Mr Gove.
SPOT ON, Chris... *That* is exactly the point!!! :clap:
Marco.
I don't get it Marco, which of your solid state amps have been unreliable?
.......ah.. Mr Gove.
What do you expect the whole party are hatched from the eggs of
http://i1308.photobucket.com/albums/s612/loonieboo1/thedevilhimself_zps706bde1c.jpg (http://s1308.photobucket.com/user/loonieboo1/media/thedevilhimself_zps706bde1c.jpg.html)
SteveTheShadow
11-10-2013, 16:19
Well not to get all party political about this, I would say that people of all political colours, have over the last thirty or so years, gone out of their way to encourage this devaluation of expertise and experience in the engineering and education fields, in particular.
The mantra is that, if you can become a sufficiently loud-mouthed gobshite, the world is your oyster.
cloth-ears
11-10-2013, 16:21
From my experience working is a service department I found that most transistor output devices fail due to poor thermal conductivity (notwithstanding those that were abused). Some of the older silicone thermal compound’s tended to dry after some year’s service. The amp would run for ages then suddenly blow as a result of thermal runaway. Any vintage SS amp should (IMHO) have the compound and thermal washers changed for a modern equivalent. This done a well designed SS amp should last a lifetime or three without incident.
Oldpinkman
11-10-2013, 16:25
Hey
Thread drift boys!! Don't for goodness sake let my missus near this thread. She's just had an ofsted.
Back to valves and why we love em...:ner:
The mantra is that, if you can become a sufficiently loud-mouthed gobshite, the world is your oyster.
Very true also having a personal sob story that you can bleet and cry about in public helps no end:lol:
X fuctor culture :vomfest:
Indeed... It's important that Jez's rather dogmatic (understandably commercially biased) outburst is put into proper perspective.
Furthermore, on the subject of facts, here's a REAL one:
The FACT is, if it were genuinely a scientific fact that solid-state amps are more reliable than valve ones, then it would have been an impossibility that the two most reliable amplifiers I've owned to date have been valve-based.
Not at all, any more than it's a fact that cigarettes are safe just because some people can smoke 50 a day and not develop lung cancer.
Hey
Thread drift boys!! Don't for goodness sake let my missus near this thread. She's just had an ofsted.
what a useless bunch of:wanker:'s they are.
rant over back to them valves:lol:
Paul
PS come on pinky whats the Intergal like then:eyebrows:
anthonyTD
11-10-2013, 16:32
And for my part, i apologize,
The fact is; either technology can and will fail at some point, in ways that can be trivial, or catastrophic...
As you were...:)
realysm42
11-10-2013, 16:50
What are a valves death throes like, do they just sound pants, or something more sinister?
In my experience they all go their own way some just fade away leaving one channel quieter , some start to sound all distorted and glow brighter , Ive had a 6C33B split its glass envelope like a terrys chocolate orange, not pretty and very scarey ,
Paul
I think one or two people are struggling with the extrapolation of your own personal experience into a 'universal truth' Marco.
Indeed - it's amazing how one's words are interpreted when the 'brains' (and I use that term loosely) of certain individuals are automatically 'tuned' to be prejudiced! ;)
Marco.
Not at all, any more than it's a fact that cigarettes are safe just because some people can smoke 50 a day and not develop lung cancer.
Hi Joe,
You're missing the point (as indeed are others elsewhere).
Jez originally stated it was a scientific fact that solid-state amplifiers are more reliable than their valve counterparts (although we've since discovered that he was referring only to the valves themselves, not the whole amplifier design) - ergo as facts are indisputable, it would've been totally impossible for me to have experienced the contrary.
Quite simply, as talented as I am (lol), even I am not capable of experiencing the impossible, which is what would've been happening had what Jez said been true!
However, quite clearly, unless I've somehow 'imagined' that the most reliable amps I've owned to date are the two valve ones I'm using now, then said 'scientific fact' is nothing of the sort, just the same as it's NOT A FACT that simply because you've avoided contracting lung cancer so far, from smoking 50 cigarettes a day, it's safe to smoke cigarettes.
Marco.
Bombast, fury and the "I know everything about everything so bollocks to you" type attitude will reduce this world to rubble in the end.
Good rant, Steve, and I wholeheartedly agree with your sentiments. However, I fail to see any relevant examples here of that behaviour, if indeed that is what you were getting at?
I often feel similar disdain towards some so-called 'experts' (and here I'm not referring to Jez, just in case there is any mistake) whose blinkered arrogance vastly outweighs any evidence of their 'expertise'! ;)
Marco.
however, in conventional transistor based designs it is of great importance to employ additional circuitry for protection in the event of a device going bad, in most cases, this would be in the form of a thermal protection switch mounted to the output devices themselves, or their heat sinks,which in turn will switch off the unit when the temperature of the devices reach a state of temperature which is deemed unacceptable etc, and or a DC detection circuit, which will' [hopefully] in the event of a device failing, also shut down the unit or its output stage, this can be the only sure way of protecting any speaker unit connected, most modern well designed solid state amps employ either one or both, which is very re-assuring, especially if you are using a very cherished or expensive pair of speakers...
But, if such an unfortunate thing were to happen, and heaven forbid, some speakers were to catch fire as a result, surely it would be their fault for not being 'robust' enough to handle the fault conditions? ;)
Marco.
I don't get it Marco, which of your solid state amps have been unreliable?
Where do you want me to start, Neil?
I'm of course referring to some of the solid-state amps I've owned in the past, including those from NAD, Denon, Cyrus, Arcam, Linn, MF, Creek, Roksan (and others) - all of which have failed in some way where my Croft and Tube Distinctions valve amps haven't, during a much longer period of ownership, despite them using valves, and therefore proves that it is NOT a scientific fact that SS amps are automatically more reliable.
The fact is (since we're dealing in facts), there must be something else in the design of SOME solid-state amps which makes them less reliable than SOME valve amps, even after allowing for the more unpredictable reliability of the valves themselves, otherwise I wouldn't have experienced what I have done, or Dave, as he outlined in post #68:
http://theartofsound.net/forum/showthread.php?28404-Valve-amps-do-measurements-tell-it-all&p=489682#post489682
Simples!! :)
Marco.
Can we put this one to bed?
A valve has a finite lifespan, and is expected to be replaced as as a matter of course after, say, 3000 hours for a power valve, and around 10,000 hours for small signal valve to assure reliability of a device such as an amplifier. The life of a transitior is so much longer that they can last an indefinate period without maintenance provided that they are also operated within their specificatons. That is indisputable. A valve amplifier can be operationally 'reliable', meaning that unplanned or random failures can be infrequent assuming planned maintenance action is taken. Reliability can be calculated using well established formal mathematical methods for both techologies. In the common definition of reliability, meaning how long does something work for before it breaks, valves are not comparable to equivilent solid state products.
My valve amps have been reliable because I have a loft box full of part-used or fully used up valves that have been swapped before failure. If I left it on continuously, as I could with SS device, without replacing parts then it would most likely fail functionally inside two years at most.
A knoweldgable engineer, such as I am Jez is, can take a particular transistor or other component and design a circuit that will not only be 'reliable' in the subjective sense, but he can work out the lifespan of the circuit and it's failure rate with a high degree of confidence and furthermore he will be able to engineer a circuit that can be assured to have a SPECIFIED lifespan and failure rate. Thank god for that otherwise the devices that support our modern world simply wouldn't work. That is ENGINEERING as applied science.
This isn't a clash of valid viewpoints. Simply, Jez is completely correct in what he said by any sensible measure. He is 'keeping it simple' but looking at things statistically there really isn't an argument to be made. To try and traduce his statements and experience based on Marcos or anyone elses singular, personal experience is just nonsense. I do get weary of this anti scientific bollocks that seems to be (wrongly) part and parcel of the subjectivist movement. In my opinion it mirrors wider trends in society in that it has become a very prevalent mindset that a body of knowledge and skill can be ignored and argued against by anybody and everybody just because everyone can have a viewpoint and opinion. Opionion and fact have become largely interchangable in discussion, and worse still, many don't really appreciate that there is a difference.
I like my valve amps because they tend not to enhance harshness and to me have a natural tonality with voices that I like. It could be an artifact of distortion, reduced levels of global feedback, better slew rates or whatever - but really I am more interested in the outcome than the technology (I get enough of that through my other work and personal interests). I just happened to have found something that does what I like, and for the moment that is based on valves.
Cheers,
Alex
This isn't a clash of valid viewpoints. Simply, Jez is completely correct in what he said by any sensible measure. He is 'keeping it simple' but looking at things statistically there really isn't an argument to be made. To try and traduce his statements and experience based on personal experience is just nonsense.
Well, Alex, he's completely correct about the former, in that valves themselves are inherently less reliable than transistors. However, quite clearly, when said transistors are incorporated into the design of a working solid-state amplifier, other factors come into play which results in some of such amplifiers not being as reliable as *some* valve amplifiers.
Otherwise, how do you explain the results of my experience and also that of hifi dave's? I'm sure, in that respect, we're not alone.
Essentially, the crux of the matter is that while it is an undisputable scientific fact that transistors, in isolation are more reliable devices than valves, it is NOT an indisputable fact, when either device is incorporated along with other electronic components inside an amplifier, that it *automatically results overall in a more reliable amplifier.
Furthermore, since none of us can use valves or transistors in isolation, and expect a sound to be heard, then how either device is successfully incorporated into a working amplifier, in terms of not only achieving high-fidelity sound, but also in optimising the reliability of the amplifier, is fundamentally what is of most importance to us as audio and music enthusiasts! :exactly:
Marco.
*Hopefully someone will eventually suss why I'm continually highlighting the word 'automatically'!! ;)
hifi_dave
11-10-2013, 19:35
I'm no engineer but I believe if a valve amp is well designed, the circuit doesn't stress the components and it is properly constructed with good quality parts, it should be as reliable as a good SS amp. Of course, valves have a finite life but this may be many years and can be considered a 'consummable' as are cartridges or (taking the car analogy) tyres, spark plugs, bulbs and wipers.
SteveTheShadow
11-10-2013, 19:38
Can we put this one to bed?
This isn't a clash of valid viewpoints. Simply, Jez is completely correct in what he said by any sensible measure. He is 'keeping it simple' but looking at things statistically there really isn't an argument to be made. To try and traduce his statements and experience based on Marcos or anyone elses singular, personal experience is just nonsense. I do get weary of this anti scientific bollocks that seems to be (wrongly) part and parcel of the subjectivist movement. In my opinion it mirrors wider trends in society in that it has become a very prevalent mindset that a body of knowledge and skill can be ignored and argued against by anybody and everybody just because everyone can have a viewpoint and opinion. Opinion and fact have become largely interchangable in discussion, and worse still, many don't really appreciate that there is a difference.
Cheers,
Alex
Amen to that Alex.
I am just as much a subjectivist as anyone, but you have to start with good engineering or else subjectively your system will sound like garbage. That I'm afraid is a fact.
In schools we as teachers are required by the National Curriculum, to teach students the difference between fact and opinion, not only in English lessons but also in such areas as ICT and the use of search engines for research purposes when doing projects. The amount of ill-informed, opinionated stuff, students copy and paste into their work and then try to pass off as fact is depressing. By the time my colleagues and I have finished with them, they have become a little bit more discriminating about who is to be believed and who the flim-flam merchants are. Sometimes we feel we are fighting a losing battle, as the one who has the biggest mouth and the most persistent message is often the biggest influence on their thinking.
I'm no engineer but I believe if a valve amp is well designed, the circuit doesn't stress the components and it is properly constructed with good quality parts, it should be as reliable as a good SS amp. Of course, valves have a finite life but this may be many years and can be considered a 'consummable' as are cartridges or (taking the car analogy) tyres, spark plugs, bulbs and wipers.
I'm also no engineer, but as an experienced audio enthusiast and user of end products, I agree with the above quite simply because it reflects the results of my (extensive) practical experience :)
Marco.
Well, Alex, he's completely correct about the former, in that valves themselves are inherently less reliable than transistors. However, quite clearly, when said transistors are incorporated into the design of a working solid-state amplifier, other factors come into play which results in some of such amplifiers not being as reliable as *some* valve amplifiers.
Otherwise, how do you explain the results of my experience and also that of hifi dave's? I'm sure, in that respect, we're not alone.
Essentially, the crux of the matter is that while it is an undisputable scientific fact that transistors, in isolation are more reliable devices than valves, it is NOT an indisputable fact, when either device is incorporated along with other electronic components inside an amplifier, that it *automatically results overall in a more reliable amplifier.
Marco.
*Hopefully someone will eventually suss why I'm continually highlighting the word 'automatically'!! ;)
Marco,
Ok, two points here. There are plenty of people who can design reliable transitior amplifiers - it is all about the application and quality of the engineering. As a case in point, my MF A100 is probably one of the very few that haven't blown up (yet) and their reliability in the field has been atrocious by all accounts. This is a result of the design, engineering (or lack of it) and specification of the product. There are doubtless many other examples within the HiFi industry of premature failure as a result of either poor design and engineering practice, or deliberate, considered design decisions taken for whatever reason (cost, sound quality etc) that are likely to compromise reliability.
In most engineering disciplines, formal evaluation of the reliability of a design solution is a core part of the practice and there is a huge wealth of knowledge and know-how that ensures that the reliability of a product is predicable attribute. In audio, we seem to accepting of poor engineering practise, maybe because sound quality is paramount to the audiophile and everything else comes a distant second. We commonly accept a level unreliability that we certainly wouldn't from a television for example
Valve amplifiers do have the advantage of simplicity. Accepting that valves are a consumable, there isn't any inherent reason why they shouldn't also be reliable in the sense of predicability, other than perhaps accelerated thermal ageing of some components and the fact that HT voltages tend to be somewhat more stressful for components. Both factors can be designed around to deliver good reliability. Valves do suffer from a higher rate of random failure in general terms when they fail they can and do suffer collateral damage needing repair.
There are lots of poorly engineered products of both types out there, and good examples, but to an engineer nothing is 'automatic' about a device continuing to work as this is as a function of the design and product engineering process.
Cheers,
Alex
Marco,
Ok, two points here. There are plenty of people who can design reliable transitior amplifiers - it is all about the application and quality of the engineering. As a case in point, my MF A100 is probably one of the very few that haven't blown up (yet) and their reliability in the field has been atrocious by all accounts. This is a result of the design, engineering (or lack of it) and specification of the product. There are doubtless many other examples within the HiFi industry of premature failure as a result of either poor design and engineering practice, or deliberate, considered design decisions taken for whatever reason (cost, sound quality etc) that are likely to compromise reliability.
In most engineering disciplines, formal evaluation of the reliability of a design solution is a core part of the practice and there is a huge wealth of knowledge and know-how that ensures that the reliability of a product is predicable attribute. In audio, we seem to accepting of poor engineering practise, maybe because sound quality is paramount to the audiophile and everything else comes a distant second. We commonly accept a level unreliability that we certainly wouldn't from a television for example
Valve amplifiers do have the advantage of simplicity. Accepting that valves are a consumable, there isn't any inherent reason why they shouldn't also be reliable in the sense of predicability, other than perhaps accelerated thermal ageing of some components and the fact that HT voltages tend to be somewhat more stressful for components. Both factors can be designed around to deliver good reliability. Valves do suffer from a higher rate of random failure in general terms when they fail they can and do suffer collateral damage needing repair.
There are lots of poorly engineered products of both types out there, and good examples, but to an engineer nothing is 'automatic' about a device continuing to work as this is as a function of the design and product engineering process.
I completely agree with everything you've written there, Alex. However, we're still somewhat at cross purposes, and so going round in circles... I'll have one more stab at explaining myself before giving up.
My initial objection was to Jez's reply to me here: http://theartofsound.net/forum/showthread.php?28404-Valve-amps-do-measurements-tell-it-all&p=489639#post489639 .... where he wrote:
Simply wrong Marco. It's a scientific fact that solid state is a lot more reliable than valves. Simple as that.
Apart from being rather miffed that my relevant and valid experience in that area was rather inconsiderately being dismissed as 'wrong', when nothing I had written in the post he quoted was in fact wrong (it was simply what I had experienced to date), had Jez wrote instead: "It's a scientific fact that transistors are more reliable devices than valves. Simple as that", then there would've been no argument.
However, it was the implication (or perhaps me misconstruing what he had written) that ALL solid-state amplifiers are automatically more reliable than ALL valve amplifiers (as experience tells me to the contrary), which sparked my indignation!
Do you see where I'm coming from now? If not, I'll have an early night and go to bed!! :D
Marco.
Yes, I get it :D
... but I still believe that solid state amps in general are probably more reliable than solid state amps, even though that runs contrary to my own personal experience.
For humourous reasons only..
Old Trio amp - caught fire
NAD 3130 - broke down after a party
B&0 3000 - total failure, protection circuits triggered at switch on
MF A100 - first sample had motorboating instability in the phono stage. Second sample has developed a crackling volume control
Cyrus 2/PSX - volume control failure, MC/MM switch failed
Rogue Metis pre-amp - never did get rid of the hum loop
Rogue Stereo 90 - intermittent crackle that I'm still trying to get fixed
C-J PV-15 pre-amp - problems with RH channel socket
C-J LP125sa - no faults so far.. too new to tell yet
Total reliability of my hifi amplification (long-term) - 0%
Total valve amp reliability 0%
total solid state reliability 0%
:lol::lol::lol:
Yes, I get it :D
At last!! :yay: :yay:
... but I still believe that solid state amps in general are probably more reliable than solid state amps, even though that runs contrary to my own personal experience.
Sure, although I know you didn't mean to refer to the same amplifier type twice! ;)
However, for me as a mere end user of product, not as an engineer or electronics designer, the practical experience gained through USING equipment is everything - and it is that, including what I've learned over many years from my subjective listening experiences, which forms the basis of all my opinions in audio.
That will always mean more to me than what 'scientific facts' supposedly say to the contrary, unless I consider said scientific facts as being irrefutable.
For humourous reasons only..
Old Trio amp - caught fire
NAD 3130 - broke down after a party
B&0 3000 - total failure, protection circuits triggered at switch on
MF A100 - first sample had motorboating instability in the phono stage. Second sample has developed a crackling volume control
Cyrus 2/PSX - volume control failure, MC/MM switch failed
Rogue Metis pre-amp - never did get rid of the hum loop
Rogue Stereo 90 - intermittent crackle that I'm still trying to get fixed
C-J PV-15 pre-amp - problems with RH channel socket
C-J LP125sa - no faults so far.. too new to tell yet
Total reliability of my hifi amplification (long-term) - 0%
Total valve amp reliability 0%
total solid state reliability 0%
:lol::lol::lol:
Hehehehe - love it!!
Marco.
Alan Sircom
11-10-2013, 21:33
I think a lot of this hangs on whether someone considers a valve as a component or as a consumable. If it's viewed as a component, a valve amplifier looks extremely unreliable compared to a solid-state design, because a pair of EL34s will generally need replacing far more often than a J-FET. If the valve is viewed as a consumable, then the reliability of any design is more to do with the design, implementation and build of the product, than the type of amplifier device used.
I know of solid-state designs of the past that used to blow output devices on an bi-monthly basis, and valve designs that are incredibly reliable. Generally however, if the designer knows what they are doing, and there's no trying to cut costs by using below-par components in the manufacturing stage, both should provide a long and robust life.
That said, I doubt any valve amplifier ever made could match something like a Quad 303 for dogged reliability. Some of those amplifiers have been used as work-horses for the last 40-45 years without any down-time.
I have owned many SS amps, some good'uns and not so good'uns, over a period of 35 years and in all that time I have only ever had one fail. The offending article was a Marantz amp hailing from the mid eighties (I forget the model but it was certainly not high end by any stretch of the imagination, plus it had had a hard life before I snapped it up from a car boot sale for three quid). The only valve amp I've owned has developed a few faults, none of which I can identify as I have little knowledge or experience of valve amplification. I draw no conclusions from this other than that I have been lucky so far as SS equipment is concerned and blindingly unlucky on the flipside.
Incidentally, my gear is rarely switched off unless I am moving or servicing it. Green it is not however it reduces the chance of failure due to thermal cycling ;)
Can I suggest that there are a few versions of "Reliability" in use.
Valves, have a specified lifetime, thats part of their design and instructions for use. If you use a valve past its intended lifetime and it fails, its not a question of reliability, its a question of misuse. Thats why valves are designed to fit in a socket, its a integral part of their design that they are expected to be replaced. A transistor on the other hand has a much longer service life, so they tend to be fitted in such a way that they are not expected to be removed during the lifetime of the equipment they are used in.
Valves have a specified maximum voltage and current specification, but they are remarkably good at surviving use outside of their design window, and often can be used for a long time with no ill effect running at 150% of anode voltage, or power dissipation. Solid state parts on the other hand do not (and are not expected to) survive well when used outside their service window. Exceed max voltage by 5% and they make a very fast acting fuse. If a transistor fails because its limits are exceeded its failure is again not a question of reliability, but of misuse.
In the way reliability is being used in this thread, both these points could be (incorrectly) used to suggest that both valve and solid state parts are less reliable than the other.
No one suggests a car tyre is unreliable because it wears out after 60,000 miles if thats the expected lifetime for it.
Alan Sircom
11-10-2013, 21:43
I have owned many SS amps, some good'uns and not so good'uns, over a period of 35 years and in all that time I have only ever had one fail. The offending article was a Marantz amp hailing from the mid eighties (I forget the model but it was certainly not high end by any stretch of the imagination, plus it had had a hard life before I snapped it up from a car boot sale for three quid). The only valve amp I've owned has developed a few faults, none of which I can identify as I have little knowledge or experience of valve amplification. I draw no conclusions from this other than that I have been lucky so far as SS equipment is concerned and blindingly unlucky on the flipside.
Incidentally, my gear is rarely switched off unless I am moving or servicing it. Green it is not however it reduces the chance of failure due to thermal cycling ;)
I have had more solid-state amplifiers fail on me than valve amplifiers, but if you view this figure in proportion to the number of solid-state and valve designs I've tested, I've had more valve amps fail on me than solid-state amps.
A solid-state amp did the most physical damage when it went 'bang', but it took a valve amp doing the same to put me in hospital.
Alan Sircom
11-10-2013, 21:53
No one suggests a car tyre is unreliable because it wears out after 60,000 miles if thats the expected lifetime for it.
No, but if it wore out after 20,000 miles, you'd be upset. And that's the problem with a lot of new valves - terrible QC.
walpurgis
11-10-2013, 22:47
I think a lot of this hangs on whether someone considers a valve as a component or as a consumable.
It's a consumable component!
Having said that, I've never had a valve fail, despite having run some very old amps with truly ancient valves in for many years. In fact I've very, very seldom had any serious equipment failures and I've been using various Hi-Fi for over forty years.
Oldpinkman
12-10-2013, 07:29
I don't believe you lot. I pop out for a couple of hours to see my mates at a blues club, and when I get back you're still bickering about valve reliability and whether marcos experiences are the basis for a universal engineering law.
How about we accept even flaky old valves can survive long enough for us to have a decent listen and consider
Do valves sound better?
If so , why?
How do some solid state amps sound "valve like"
Is "sounds better" hifi if it is not as accurate a version of the unamplified source as "sounds not so good"?
Is it accurate to distort something? (Is distortion accuracy? )
Oh & alex. Did you know the moon landings were faked in a studio? The kids at sues school do ;)
I think a lot of this hangs on whether someone considers a valve as a component or as a consumable.
I tried using a valve amp without valves once. It was eerily silent. 'Inky blackness' doesn't begin to describe it.
cloth-ears
12-10-2013, 08:42
Distortion should be looked at as “difference”. If we measure (look at) the signal from say a CD as it enters the amplifier then the signal that comes out should be the same but much bigger. Any difference between the signals is a distortion, a distortion of the truth. Although some think otherwise that difference can be measured.
anthonyTD
12-10-2013, 08:42
:lol::lol::lol:
I tried using a valve amp without valves once. It was eerily silent. 'Inky blackness' doesn't begin to describe it.
I think a lot of this hangs on whether someone considers a valve as a component or as a consumable. If it's viewed as a component, a valve amplifier looks extremely unreliable compared to a solid-state design, because a pair of EL34s will generally need replacing far more often than a J-FET. If the valve is viewed as a consumable, then the reliability of any design is more to do with the design, implementation and build of the product, than the type of amplifier device used.
I know of solid-state designs of the past that used to blow output devices on an bi-monthly basis, and valve designs that are incredibly reliable. Generally however, if the designer knows what they are doing, and there's no trying to cut costs by using below-par components in the manufacturing stage, both should provide a long and robust life.
That said, I doubt any valve amplifier ever made could match something like a Quad 303 for dogged reliability. Some of those amplifiers have been used as work-horses for the last 40-45 years without any down-time.
Excellent post, Alan (and indeed, Nick). Your contributions to the discussion have put a realistic balance on the subject, which is all I sought.
There would've been no argument from me had Jez made it clear from the start that, in terms of reliability, he was talking purely about valves versus transistors, in isolation. The problem I had was when it appeared that his scientific fact was being moved to apply also to complete amplifiers, inferring that the valve variety would be automatically less reliable than those containing transistors, when personal experience of mine, over many years, had proved the contrary.
Moving on now from that part of the discussion, could someone 'in the know' tell me what the expected lifespan is of your average transistor, or more specifically, if 15 years of use inside an amplifier (the length of time I obtained from using a matched quad of GEC KT88s in my valve amp) would be considered as acceptable?
It should also be noted that said GEC output valves didn't go pop after 15 years - I simply sold them on before changing to KT120s, so goodness knows how long they'd have lasted if I'd kept them! Furthermore, before selling them, Anthony put them in his valve tester (so I could advertise them on ebay with all the relevant measurements) and they still tested at nearly full output!!! :eek:
What I'm getting at here is that there could be an argument for saying, in some circumstances (depending on the circuit they're used in and how hard they are driven), that the best vintage (NOS) valves could last as long as some transistors.
Marco.
All I'm going to say is I play in a band and us guitarists use valve and you can imagine the abuse they take over the years being lugged around pushed and thrown around yet the only problems we've had was the odd valve going down personally I feel valves amps are very reliable and look at big bands all the guitarists use valve amps being wheeled and flown all over the world so can't be that bad.
I don't believe you lot. I pop out for a couple of hours to see my mates at a blues club, and when I get back you're still bickering about valve reliability and whether marcos experiences are the basis for a universal engineering law.
It was never about that, Richard (so please stop taking things out of context); merely that I considered it unacceptable, that in 25+ years of using both valve and SS amps, my valid experiences were being inconsiderately and unfairly dismissed as 'wrong'. However, that issue has now been dealt with satisfactorily, and so we move on! :)
Marco.
Oldpinkman
12-10-2013, 09:38
Sure - no problem - it was a long thread to catch up on
So I repeat
Do valves sound better?
If so , why?
How do some solid state amps sound "valve like"
Is "sounds better" hifi if it is not as accurate a version of the unamplified source as "sounds not so good"?
Is it accurate to distort something? (Is distortion accuracy? )
;)
Another thing to consider is that well designed valve equipment is designed to be repairable if a valve does fail in a bad way. Normally its just replace a resistor and sometimes a cap and its good to go, thats certainly the case for a lot of musical instrument amps and circuits from the 60's and earlier. When a transistor lets go in a SS amp, it often takes a lot more of the circuit with it, so repair is a lot harder.
The worst case is a lot of the valve amps from the 80's and 90's where designers assumed that SS ideas could improve valve amps, so things like output stages on PCB' and the worst, solid state bias control circuits. Normally undocumented (what, give out the circuit), and when the valve fails (as it never gets checked as it never needs biasing) it takes all that out and the amp is junk.
Good point, Nick, and something probably most of us wouldn't have considered! :)
Do you have any views on what I wrote in my previous post regarding an acceptable lifespan for your average transistor, and whether it could be considered that, in the right circuit, some of the best NOS valves could last as long as some transistors?
Marco.
Sure - no problem - it was a long thread to catch up on
So I repeat
Do valves sound better?
If so , why?
How do some solid state amps sound "valve like"
Is "sounds better" hifi if it is not as accurate a version of the unamplified source as "sounds not so good"?
Is it accurate to distort something? (Is distortion accuracy? )
;)
Well I had a go at answering this in post 28 but by that point we had already got bogged down in the pointless reliability argument:
A little bit of 2nd harmonic adds a euphonic quality to the sound. Indeed Douglas Self proposed a transistor amp wiith a 'niceness' control that allowed the user to add 2nd harmonic to taste.
You don't see this commercially because it is obviously not aspiring to high fidelity but valve amps and some transistor amps will have a little distortion that will do the job just as well, except you don't have variable adjustment.
Essentially what I am saying is that the slightly distorted sound can be more engaging to listen to but that the 'anodyne' sound is actually the more accurate rendition
Ali made the point that SET amps are amongst the best sounding he has ever heard so how can they not be 'hi-fi' and the point is you cannot have fidelity to the recording if you are using an amp that audibly distorts, even if that distortion makes it sound fantastically good. It's a bit like Red Dwarf's 'Better than Real Life'. As a concrete and specific example take Bowie's 'Fashion.' Corking guitar contribution from Robert Fripp and a great recording overall. With my XTZ pre-amp it sounds like a stereo playing Fashion. The guitar part is there, somewhat back in the mix, the sound cannot be faulted but is not exciting. With the NVA pre the guitar part is more forward, superbly rendered, you notice it and appreciate the tone and the playing. With the Croft pre-amp it sounds like Fripp has plugged his guitar directly into the hi-fi - quite amazing but I know this recording and that is not what it really sounds like.
Oldpinkman
12-10-2013, 09:56
Good point, Nick, and something probably most of us wouldn't have considered! :)
Do you have any views on what I wrote in my previous post regarding an acceptable lifespan for your average transistor, and whether it could be considered that, in the right circuit, some of the best NOS valves could last as long as some transistors?
Marco.
I thought the issue had been dealt with satisfactorily and we were moving on!
(And sorry Marco, my earlier post wasn't intended as having a pop - just a one-line precis of a lot of thread activity in my absence) :)
Oldpinkman
12-10-2013, 09:58
Well I had a go at answering this in post 28 but by that point we had already got bogged down in the pointless reliability argument:
A little bit of 2nd harmonic adds a euphonic quality to the sound. Indeed Douglas Self proposed a transistor amp wiith a 'niceness' control that allowed the user to add 2nd harmonic to taste.
You don't see this commercially because it is obviously not aspiring to high fidelity but valve amps and some transistor amps will have a little distortion that will do the job just as well, except you don't have variable adjustment.
Essentially what I am saying is that the slightly distorted sound can be more engaging to listen to but that the 'anodyne' sound is actually the more accurate rendition
Ali made the point that SET amps are amongst the best sounding he has ever heard so how can they not be 'hi-fi' and the point is you cannot have fidelity to the recording if you are using an amp that audibly distorts, even if that distortion makes it sound fantastically good. It's a bit like Red Dwarf's 'Better than Real Life'. As a concrete and specific example take Bowie's 'Fashion.' Corking guitar contribution from Robert Fripp and a great recording overall. With my XTZ pre-amp it sounds like a stereo playing Fashion. The guitar part is there, somewhat back in the mix, the sound cannot be faulted but is not exciting. With the NVA pre the guitar part is more forward, superbly rendered, you notice it and appreciate the tone and the playing. With the Croft pre-amp it sounds like Fripp has plugged his guitar directly into the hi-fi - quite amazing but I know this recording and that is not what it really sounds like.
Interesting
So is the "Art of Sound" taking flawed components to create a pleasing balance - rather than striving for improved components to achieve a "high fidelity" reproduction of real music? :scratch:
Interesting
So is the "Art of Sound" taking flawed components to create a pleasing balance - rather than striving for improved components to achieve a "high fidelity" reproduction of real music? :scratch:
Sorry, that's complete and utter nonsense, and the age-old chestnut of valves creating a "pleasing" sound is, with the right equipment, equally inaccurate. I have to go out now, but will come back to this later.
Marco.
realysm42
12-10-2013, 10:07
Surely the art of sound is defined by everyone on a personal basis. I might like what you'd hate and so, as with all art, beauty is in the eye (ear) of the beholder.
I don't care what I use to get 'there' as long as it makes me smile.
. As a concrete and specific example take Bowie's 'Fashion.' Corking guitar contribution from Robert Fripp and a great recording overall. With my XTZ pre-amp it sounds like a stereo playing Fashion. The guitar part is there, somewhat back in the mix, the sound cannot be faulted but is not exciting. With the NVA pre the guitar part is more forward, superbly rendered, you notice it and appreciate the tone and the playing. With the Croft pre-amp it sounds like Fripp has plugged his guitar directly into the hi-fi - quite amazing but I know this recording and that is not what it really sounds like.
I take the point about minimising distortion, but, unless you were present at the recording session and/or have access to the master tapes, how can you (or anyone else) know what the the recording 'really sounds like'?
I take the point about minimising distortion, but, unless you were present at the recording session and/or have access to the master tapes, how can you (or anyone else) know what the the recording 'really sounds like'?
That's a fair point and I figured that someone would make it. Having heard professional recordings both pre- and post master (on CD) I would say the difference is mainly one of dynamics, in that dynamics are reduced by the mastering process. In other words a well-mastered digital recording on CD is pretty truthful to the original IME. I have heard the track I mentioned many times over many years on a ton of different equipment. If the presentation through the Croft is right then everything else is wrong.
SteveTheShadow
12-10-2013, 10:41
Recreating the sound of real music by playing recordings through loudspeakers is an impossibility. It ain't gonna happen.
Why do we think the adjective "high" precedes fidelity?
We buy/build the gear that takes us to where we want to be in relation to the "sound" we have in our heads.
That is the quest, whether it be via valves or transistors, single-ended, push-pull, OTL or whatever.
If someone else likes a different presentation, who is anyone to say they are wrong?
After you have done your engineering, to try to analyse further, any of this is a total waste of time. you tweak your system to fulfil your needs, end of.
A system should allow you to buy the music you like, enjoy it, regardless of recording quality, maybe share it with friends and expand your musical horizons.
A system that does not allow you to do that or makes ANY SINGLE ONE of your favourite recordings unlistenable is no use, period.
It always makes me laugh when folk write about how their latest upgrade makes their "best" recordings sound fantastic but now a lot of their collection has become unlistenable. That is no upgrade in my book. let's leave them with their illusions, they harm nothing but their ears and bank balance.
To me this is right at the core of the enigma of hi-fi. If we accept that the absolute sound is unobtainium we can relax, and plough our own furrow.
I couldn't give a monkey's why valves sound different to transistors. It is interesting but unimportant. I believe I went a little way towards explaining the differences way back in the thread. I like the looks, the red glow on a winter's evening, the evocation of things far off and long ago, of simpler, happier times, of roast beef and Two Way Family favourites. Best of all, for me, valves bring recorded music alive, like nothing else on this planet and will continue to do so until the last cathode sleeve sputters to a stop.
Recreating the sound of real music by playing recordings through loudspeakers is an impossibility. It ain't gonna happen.
.
Steve - I agree. But recreating the sound of the recording is possible. Some choose to enhance the sound of that recording, be it by using equalisation or equipment that is 'voiced' either via distortion or other artifacts. Nothing wrong with that approach, as you say we all have that sound in our heads that we are looking for and this varies from person to person. But 'High Fidelity' means 'Highly Truthful', so logic dictates that minimising noise and distortion are fundemental requirements for true 'high fidelity'.
Recreating the sound of real music by playing recordings through loudspeakers is an impossibility. It ain't gonna happen.
Why do we think the adjective "high" precedes fidelity?
We buy/build the gear that takes us to where we want to be in relation to the "sound" we have in our heads.
That is the quest, whether it be via valves or transistors, single-ended, push-pull, OTL or whatever.
If someone else likes a different presentation, who is anyone to say they are wrong?
After you have done your engineering, to try to analyse further, any of this is a total waste of time. you tweak your system to fulfil your needs, end of.
A system should allow you to buy the music you like, enjoy it, regardless of recording quality, maybe share it with friends and expand your musical horizons.
A system that does not allow you to do that or makes ANY SINGLE ONE of your favourite recordings unlistenable is no use, period.
It always makes me laugh when folk write about how their latest upgrade makes their "best" recordings sound fantastic but now a lot of their collection has become unlistenable. That is no upgrade in my book. let's leave them with their illusions, they harm nothing but their ears and bank balance.
To me this is right at the core of the enigma of hi-fi. If we accept that the absolute sound is unobtainium we can relax, and plough our own furrow.
I couldn't give a monkey's why valves sound different to transistors. It is interesting but unimportant. I believe I went a little way towards explaining the differences way back in the thread. I like the looks, the red glow on a winter's evening, the evocation of things far off and long ago, of simpler, happier times, of roast beef and Two Way Family favourites. Best of all, for me, valves bring recorded music alive, like nothing else on this planet and will continue to do so until the last cathode sleeve sputters to a stop.
+1 this is so true, people even prefer to stand or sit in different spots at concerts because they prefer the sound from that perspective.what is the perfect reproduction I certainly don't want my stereo to be like headphones plugged directly into the mixing desk.
Paul
SteveTheShadow
12-10-2013, 11:21
Steve - I agree. But recreating the sound of the recording is possible. Some choose to enhance the sound of that recording, be it by using equalisation or equipment that is 'voiced' either via distortion or other artifacts. Nothing wrong with that approach, as you say we all have that sound in our heads that we are looking for and this varies from person to person. But 'High Fidelity' means 'Highly Truthful', so logic dictates that minimising noise and distortion are fundemental requirements for true 'high fidelity'.
Recreating the sound of the recording is not possible, not unless you go to the studio where it was made and listen in the same control room, through the same studio monitors and have the recording engineer's own head transplanted onto your own neck. That last daft example is important, because you cannot hear what the engineer heard, so you can't recreate the original sound of the recording, only your idea of that sound.
In 1975 Carl Anthony wrote a landmark philosophical piece called "fidelity to what?"
This article is recognised in some quarters as a key work that started the whole subjectivist movement in the mid to late 70s.
That these ideas were subsequently corrupted by certain vested interests is well documented, but Carl Anthony's work still stands as a seminal piece of out of the box thinking, that changed forever, the way we approach music reproduction in the home.
That you have to get your engineering right is indisputable and as you say is a fundamental requirement to good hi-fi, but there are other things in there that no matter how we argue about it, cannot be measured in the conventional sense.
We cannot achieve the absolute sound so we tailor our systems to our internalised concept of what makes a good music system. Where's the sense denying this.
The absolute sound is a philosophical construct that has wasted countless billions of man hours over the last 50 years.
Engineering delivers low distortion and noise. The rest is up to us as individuals.
anthonyTD
12-10-2013, 11:23
Hi All,
Every circuit stamps its own character on the original signal given, whether it be subtle or excessive, all one can do as a designer, is limit this character as far as possible if the desired design concept is to keep the integrity of the original signal as close as possible to the original...
However, some designers deliberately add character to the signal, any character that was not present in the original signal is a distortion, and when you look at the process recorded music has to go through, from the beginning, ie; microphone, to preamp, to compressors, and limiters,to mixing desk etc, then it is quite easy to assume that the signal has had many distortions added to it and gone through possibly many inversions, before it even gets to the master tape, disk, or hard disk, whichever media is to be used to produce a user friendly copy...
Now, which type of amplifier is best suited to play this final abomination [as far as the original is concerned] is up to the end user, who will decide for themselves the type of added distortion the final amplification will add' and therefore be the most pleasing and communicative on a personal level...
Lets not kid our selves here...
However, there are recognized types of distortion that are UN-objectionable, even in relatively large amounts, and distortion types that are very objectionable, even in small amounts,so again, look at the design topology and pick your poison, because at the end of the day, neither is perfect by a long way...
A...
+I certainly don't want my stereo to be like headphones plugged directly into the mixing desk.
Paul
Wheras I do :) and that really is the crux of the issue - the correct approach is the one that works for you.
However, some designers deliberately add character to the signal, any character that was not present in the original signal is a distortion, and when you look at the process recorded music has to go through, from the beginning, ie; microphone, to preamp, to compressors, and limiters,to mixing desk etc, then it is quite easy to assume that the signal has had many distortions added to it and gone through possibly many inversions, before it even gets to the master tape, disk, or hard disk, whichever media is to be used to produce a user friendly copy...
Now, which type of amplifier is best suited to play this final abomination [as far as the original is concerned] is up to the end user, who will decide for themselves the type of added distortion the final amplification will add' and therefore be the most pleasing and communicative on a personal level...
Lets not kid our selves here...
...
A...
But for domestic replay purposes what happened prior to the 'final abomination' ;) is irrelevant. It's about what happens after we insert the final abomination into a CD player, or click the mouse to intiate the file.
Wheras I do :) and that really is the crux of the issue - the correct approach is the one that works for you.
Exactly :lol:
like all these discussions they can only really be settled by slapping your todger on the table and getting out the rule:)
Paul
Exactly :lol:
like all these discussions they can only really be settled by slapping your todger on the table and getting out the rule:)
Paul
Even that is academic! It is how it is used that makes a difference; ask any woman - how does one measure her perception of such things?
Even that is academic! It is how it is used that makes a difference; ask any woman - how does one measure her perception of such things?
you mean men care what women think?:scratch:
Just use what you think sounds better.
anthonyTD
12-10-2013, 12:00
Now, which type of amplifier is best suited to play this final abomination [as far as the original is concerned] is up to the end user, who will decide for themselves the type of added distortion the final amplification will add' and therefore be the most pleasing and communicative on a personal level...
Lets not kid our selves here...
However, there are recognized types of distortion that are UN-objectionable, even in relatively large amounts, and distortion types that are very objectionable, even in small amounts,so again, look at the design topology and pick your poison, because at the end of the day, neither is perfect by a long way...
A...
But for domestic replay purposes what happened prior to the 'final abomination' ;) is irrelevant. It's about what happens after we insert the final abomination into a CD player, or click the mouse to intiate the file.
SteveTheShadow
12-10-2013, 12:18
you mean men care what women think?:scratch:
Well yes they do, some of them at least.
That's why these speakers reside peacefully in our living room
http://dl.dropbox.com/u/7181882/metsathome.jpg
Essentially what I am saying is that the slightly distorted sound can be more engaging to listen to but that the 'anodyne' sound is actually the more accurate rendition[/I]
Hi Martin,
That's fine, but it's not what I mean by anodyne. I also suspect that we have different views of what is considered as "the more accurate rendition".
First of all, as Anthony TD has pointed out, no amplifier is totally free of distortion, therefore at the end of the day it's simply about choosing your 'favourite type' (as exhibited by either valve or SS varieties), or rather what is most pleasing/less intrusive, to your ears, on music reproduced. This of course makes any argument about 'accuracy' somewhat moot (as no component or system is capable of reproducing a true version of it) - and that's even before taking into consideration the fact that the most distorted components of all are the loudspeakers at the end of the chain! ;)
In that respect, how does the average audio enthusiast, who only has his or her system to use as 'test apparatus', assess which area of his or her system is responsible for creating which type of distortion? The fact is, all that can be judged is the final sound (as a whole) emitted by the loudspeakers (and then manipulated by the room) - and so in the final analysis, the sound heard at that point by the listener, is ALL the matters! Therefore, fretting over 'accuracy', in the sense that you mean it is, quite simply, a fool's errand.
In any case, in my experience, a well-designed valve amplifier can sound just as 'accurate' as any well-designed solid-state amplifier (if your benchmark is reproducing music signals as accurately as possible, as opposed to test tones), therefore most recognised measurement parameters for amplifier distortion are no more than guidelines and mean little, in terms of the sound produced by hi-fi systems, in 'real-world' listening environments.
Returning to my point about "anodyne", it is my opinion, based on considerable listening experience to both high-quality valve and SS amplifiers, over more than 25 years, that the reason for many listeners preference for the former, over the latter, is not so much about what valve amplifiers ADD to the sound, in terms of coloration, but rather what those transistor amplifiers REMOVE/'strip away', in terms of harmonic information fundamental in allowing recorded music to 'breathe', and thus sound as lifelike as possible. I cannot comment technically on the reasons for that, but simply on what I can clearly hear is MISSING (based on my benchmark of how real voices and instruments sound when un-amplified), every time I compare any good valve amplifier with its solid-state counterpart.
Therefore, when I say that, to my ears, most SS amps sound anodyne, in comparison with the best valve amplifiers, they sound that way to me because something fundamentally important in allowing recorded music to sound real (based on my understanding of such) is being REMOVED, causing said blandness, rather than it being the case that the sound is bland/anodyne because I'm missing the 'pleasing effect' of any euphonic coloration being ADDED by the use of valves. In that sense, to my ears (and probably also those of others), in the final analysis, valves, when implemented optimally, are more faithful music-making devices than transistors.
For me, forget about analysing measured distortions, at the end of the day it comes down to which sound (with valves or transistors in the equation), produced by a system reproducing recorded music, the listener considers as being the most LIFELIKE. Therefore, the question to be asked is, what technical reasons might explain why many listeners, having compared both at length, consider valves to produce a more LIFELIKE sound?
I'd like to offer up that question for debate.
After all, it's the fact that they make my favourite music sound more REAL, than transistors do, that I use valves, not because I'm being seduced by any euphonic coloration they create. Therefore, in true audiophile tradition, my motives for using valves (aside from the musical pleasure they provide) are very much based on striving for the highest level of fidelity :)
Marco.
Hi Marco
To answer some of your points (sorry I can't work out how that multi quote thing works...) :
First of all, as Anthony TD has pointed out, no amplifier is totally free of distortion
True, but some amps distort audibly and some have distortion well below audible thresholds. Both by design.
This of course makes any argument about 'accuracy' somewhat moot (as no component or system is capable of reproducing a true version of it
But with a stero hi-fi system we are attempting to reproduce a true version of the recording, not of a live sound. The engineer hears the recording through an amp and speakers just like we do.
most recognised measurement parameters for amplifier distortion are no more than guidelines and mean little, in terms of the sound produced by hi-fi systems, in 'real-world' listening environments
Yes you can have a valve amp with very low distortion. No argument there. However I disagree that measured parameters for amplifier distortion mean little in terms of the actual sound.
that the reason for many listeners preference for the former, over the latter, is not so much about what valve amplifiers ADD to the sound, in terms of coloration, but rather what those transistor amplifiers REMOVE/'strip away', in terms of harmonic information fundamental in allowing recorded music to 'breathe', and thus sound as lifelike as possible
I would suggest that it is perhaps a little of both. Added to which a good valve amp would likely be hard-wired, hand made and with a minimal but high quality component count all of which will reduce noise and improve SQ. My experience has been that good solid state power amps do not strip anything away, although I have heard this effect with transistor amplification and my view is that problem lies in the pre-amp and is a noise based rather than distortion based.
Ultimately I would prefer to have a good sound system that sounds good because it lacks noise and distortion, and not because is has benign sounding distortion deliberately added for flavour. I am not suggesting all valve amps do this, but many do and so do some solid state amps. If you are going to add flavour then the speakers are the place to do it. I'm not saying that is the right way, that is just my way and it seems to be logical to me at least :)
It seems to me that its like arguing if a book is better printed in Roman or Comic Sans, in both cases, whats important is can the structure, dialogue and emotional content be conveyed from the authors imagination to the mind of the reader? I know what a Stratocaster sounds like, but I dont know what SRV's Stratocaster sounded like, but what I do know is that some systems allow me to glimpse inside the mind of the musicians playing the music and to understand just what emotion they were trying to convey better than others. To me thats all that matters, if low distortion does that, fine, if high distortion does that, thats fine as well. As a designer I try and form some system that allows me to correlate the emotional transparency of a system with the way I measure it and understand how its operating. But as a consumer of recorded music, I dont care, all I care about is what the sound that arrives at my hears does to my mind and how it makes me feel.
Peter Walker coined the clever phase "A Straight Wire with Gain", but its nothing but another marketing slogan, no better or worst than "Source First" or "Probably the best Beer in the world". In the 50's the BBC had investigated the role of distortion and they knew how some forms mattered and did damage and some were benign. They derived methods of measuring the quality of a amplifier that were provably closer to the subjective experience of panels of listeners. But does that work get referenced today when measuring a amplifier? No, lets just look at THD, or TID, or whatever is the flavour of the month, and is easy to design towards a winning number. Any attempt to reduce the performance of an amplifier (or any complex system) to a single order of merit (or small number of them), is at best flawed, at worst a intentional attempt to mislead the consumer.
The speakers are more important to get right imo.
If they have high distortion the amp almost becomes unimportant.
That's why i would always go with the speakers first route.
Also if the speakers don't work in your room you will end up on the box swapping merry go round.
Arkless Electronics
12-10-2013, 14:03
The valves in an amp are an intrinsic part of that amp and cannot be considered in isolation. If your car keeps breaking down you would say its an unreliable car.... I've yet to meet anyone who would describe it as a reliable car with an unreliable engine!
Random failures in valves are the most common failure mechanism in valve amps and this will often cause collateral damage (blown screen grid resistors, cathode resistors, sometimes other valves in the output stage and in rare cases output or mains transformers).
Today's valves are much more unreliable than the ones we had in the past from the likes of Mullard, Brimar, GEC, Sylvania etc but even they were less reliable than transistors. As I mentioned in the article I linked to on my site, it is quite common for brand new valves to fail within minutes!
Things have got a bit better than they were 20 years ago but valve quality has some way to go yet.
Much also depends on the way a valve is used in a particular design... high HT voltages don't bode well for reliability with today's valves! Try operating modern output valves at or near the maximum ratings and see how long they last!
When I worked for Musical Fidelity I was the only one there other than Antony Michaelson who had anything to do with the valve amps they made... It was me who repaired them all, got them ready for reviews etc. The Michaelson Audio Odysseus was so unreliable that they stopped selling them after a short while. AFAIK not one lasted a month! The Chronos was a bit better but still not exactly reliable. Things got so bad that we ended up making a huge valve testing rig (designed originally by TdP literally on the bag of a fag packet! Redesigned by me 'cos it didn't work). It was quite an impressive sight to see 100 valves powered up at a time on a rig about 10' x 4' ! Even that wasn't enough and they eventually gave up...
Of course it is possible to think of examples where valves have proven reliable in a particular instance. It's also possible to think of unreliable SS amps but they are the ones that were simply badly designed or built down to a price (such as the A1 and MA50. The circuit design was fine but they needed much bigger heatsinks, bigger transformers, higher rated caps etc).
Overall though it is indeed a fact that solid state amps are much more reliable than valve ones. This is a well known and established fact which I'm amazed anyone has argued with. I've personally worked on thousands of amps and can fully verify it.
I'm not saying that all valve amps are unreliable liabilities of course.... there is reliable and reliable though ;)
Probably 10 SS amps exist for every 1 valve amp and yet about half of the repairs I get in are valve amps.... and I hardly ever see a Quad (SS one) or Naim!! ;)
I don't see how any system, however accurate, can enable you to see into the minds of the musicians; that strikes me as wishful thinking.
I don't see how any system, however accurate, can enable you to see into the minds of the musicians; that strikes me as wishful thinking.
Its sad that you dont think thats possible, and its also sad you believe its anything to do with accuracy.
It seems to me that its like arguing if a book is better printed in Roman or Comic Sans, in both cases, whats important is can the structure, dialogue and emotional content be conveyed from the authors imagination to the mind of the reader? I know what a Stratocaster sounds like, but I dont know what SRV's Stratocaster sounded like, but what I do know is that some systems allow me to glimpse inside the mind of the musicians playing the music and to understand just what emotion they were trying to convey better than others. To me thats all that matters, if low distortion does that, fine, if high distortion does that, thats fine as well. As a designer I try and form some system that allows me to correlate the emotional transparency of a system with the way I measure it and understand how its operating. But as a consumer of recorded music, I dont care, all I care about is what the sound that arrives at my hears does to my mind and how it makes me feel.
.
Nick
To take your book/typeface analogy - what if I took a boring novel and re-wrote it in street slang? It would certainly be less dull to read but it would also be a lot further away from what the author intended. The musicians either convey their emotion through the music with varying degrees of success, and the entirety of their efforts are there on the recording - attempting to then enhance it by deliberately adding distortion in the amplification section just seems wrong to me. It's cheating, it's creating a fake and it's not in keeping with the basic principle of hi-fidelity.
cloth-ears
12-10-2013, 14:13
I'm afraid you didn't make that clear. And just as Chris has said, if you make allowances for the fact that the valves will 'go pop' sometime, then where's the issue?
Quite simply, the rest of the design of a valve amplifier, tubes aside, is no more less reliable than that of an SS device, in fact in some cases a hard-wired line-only valve amp is probably MORE reliable, due to the existence of less active components, which explains not only my experiences, but also those of Chris and Dave.
Furthermore, I got more than 15 years of continual usage in my amp out of GEC KT88 output valves, so where does that fit in with your argument that output valves aren't reliable, and how does that timescale compare with the lifespan of your average transistor?
Marco.
A transistor has three legs called Base, Collector and Emitter. The flow of electricity between Collector and Emitter is controlled by a voltage applied to the Base. It is in essence a TAP or VALVE. Yes I said valve because the glowing glass bottles we call valves are so called because of these attributes. By applying a small amount of pressure to the tap (Base) you are able to control a high pressure flow. Depending on the position of the tap the amount of pressure that is allowed to flow can be accurately adjusted. In this analogy a transistor is closer to the ideal VALVE.
A transistor does not have a shelf life. Providing it is used within its Safe Operating Area (SOA) it could in theory last forever.
Arkless Electronics
12-10-2013, 14:24
Nick
To take your book/typeface analogy - what if I took a boring novel and re-wrote it in street slang? It would certainly be less dull to read but it would also be a lot further away from what the author intended. The musicians either convey their emotion through the music with varying degrees of success, and the entirety of their efforts are there on the recording - attempting to then enhance it by deliberately adding distortion in the amplification section just seems wrong to me. It's cheating, it's creating a fake and it's not in keeping with the basic principle of hi-fidelity.
+1
walpurgis
12-10-2013, 14:43
Goodness. I've just been having another read through this ever expanding thread. So much debate, yet no definitive conclusions, as you all know there won't be!
My take is that measurements may give you an idea of the expected sound, but not necessarily. And valves don't necessarily 'sound' different to transistors, it's just that the sound can have a different character depending on amp type. I've heard SS amps with a warm and atmospheric sound presentation and I've also heard some rather clinical sounding valve models (more predominantly vice versa though).
Arkless Electronics
12-10-2013, 14:54
Here's a potentially interesting conundrum (for me anyway....). If I build a valve amp that that measures so well and sounds so neutral that you can't tell it is a valve amp apart from by looking at it.... is that a good thing?
For me, an amp should add nothing and take nothing away, just amplify. If it sounds obviously "valvey" then that is a form of colouration or distortion and a bad thing...... just as if a SS amp sounds obviously SS in as much as gritty, hard, "in yer face" etc than that's also a bad thing!
This raises the issue that if I can make a valve amp and SS amp sound pretty much identical (and good) then who would the potential buyers be!!?? Especially as a SS version would almost certainly be cheaper and more reliable :scratch:
Peter Walker coined the clever phase "A Straight Wire with Gain", but its nothing but another marketing slogan, no better or worst than "Source First" or "Probably the best Beer in the world". In the 50's the BBC had investigated the role of distortion and they knew how some forms mattered and did damage and some were benign. They derived methods of measuring the quality of a amplifier that were provably closer to the subjective experience of panels of listeners. But does that work get referenced today when measuring a amplifier? No, lets just look at THD, or TID, or whatever is the flavour of the month, and is easy to design towards a winning number. Any attempt to reduce the performance of an amplifier (or any complex system) to a single order of merit (or small number of them), is at best flawed, at worst a intentional attempt to mislead the consumer.
Spot on, Nick. However, in audio some people are unwilling and/or incapable of lateral thinking or considering the shades of grey, and together with a need for certainty, absolutism, painted in broad strokes of black and white, is a far more palatable reality! ;)
Marco.
P.S Martin (Macca), with your last post, to me, we are largely in agreement (save a few finer points), so we'll leave it there :)
SteveTheShadow
12-10-2013, 15:15
Nick
To take your book/typeface analogy - what if I took a boring novel and re-wrote it in street slang? It would certainly be less dull to read but it would also be a lot further away from what the author intended. Nice one Martin-take an analogy and change its meaning to suit an agenda.
deliberately adding distortion in the amplification section just seems wrong to me. It's cheating, it's creating a fake and it's not in keeping with the basic principle of hi-fidelity.
All those electric guitarists wouldn't make very interesting music if all you had to listen to was the sound of strings against a solid body.
Deliberately adding distortion is what gives them a unique voice; but of course that's just me being facetious and is not relevant to this discussion.
Cheating? Creating a fake?
Hi-fi exists to create an artifice, an illusion. It's all a fake!
I'll say it again.
You cannot create the sound of real musicians in your living room.
Let the idea that you can, go and your musical enjoyment becomes much enhanced.
Instead of yearning for the impossible, listen to the emotion, the feeling, the presence, the tone, the timbre,
the composer's intent. That IMO is the principle of hi-fi sound reproduction. If a component improves the ability of your system to do the above, it's an upgrade, if it doesn't it's not worth your money.
If folk want to sit there in a state of hyper-anxiety, listening for the slightest fault that's their perogative
I however want to experience the pleasure of music in the home, and if I can experience that and at the same time,
feast my eyes on a set of glowing glass bottles that's a nice bonus.
The valves in an amp are an intrinsic part of that amp and cannot be considered in isolation. If your car keeps breaking down you would say its an unreliable car.... I've yet to meet anyone who would describe it as a reliable car with an unreliable engine!
I thought we'd put this part of the debate to bed? :rolleyes:
The point is, Jez, it is NOT a scientific fact that transistor amplifiers are automatically more reliable than valve amplifiers, as has clearly been proven by the experiences to the contrary of people here.
No-one's really interested in that, in isolation, transistors are factually the more reliable devices. It's what happens when either device is incorporated inside the design of a fully working amplifier that matters most and what concerns audio enthusiasts - and in that respect, transistor designs are not infallible, or necessarily in all instances more reliable than their valve counterparts.
End of!
Marco.
This raises the issue that if I can make a valve amp and SS amp sound pretty much identical (and good) then who would the potential buyers be!!?? Especially as a SS version would almost certainly be cheaper and more reliable :scratch:
Does anyone remember TdP basically making the same amp (or as similar as possible) as a SS and a valve version, to prove there was, in fact, no audible difference? At least I think that is why he did it.
Guess which version the HFN reviewer preferred? This was some years ago...
The Grand Wazoo
12-10-2013, 15:35
1993 - the first Yoshino amps
Arkless Electronics
12-10-2013, 15:37
I thought we'd put this part of the debate to bed? :rolleyes:
The point is, Jez, it is NOT a scientific fact that transistor amplifiers are automatically more reliable than valve amplifiers, as has clearly been proven by the experiences to the contrary of people here.
No-one's really interested in that, in isolation, transistors are factually the more reliable devices. It's what happens when either device is incorporated inside the design of a fully working amplifier that matters most and what concerns audio enthusiasts - and in that respect, transistor designs are not infallible, or necessarily in all instances more reliable than their valve counterparts.
End of!
Marco.
Yes it is! it's a 100% certainty! I will not back down on this as 40 years of experience, + repairing amps everyday + studying electronics for all this time + working for well known manufacturers + running my own business in amp repairs for many years has given me the knowledge and experience to be able to say with absolute certainty that I am right!!
End of!
1993 - the first Yoshino amps
Yeah - the reviewer preferred the valve version, if I remember correctly - which I'm pretty sure I do:)
Nice one Martin-take an analogy and change its meaning to suit an agenda.
All those electric guitarists wouldn't make very interesting music if all you had to listen to was the sound of strings against a solid body.
Deliberately adding distortion is what gives them a unique voice; but of course that's just me being facetious and nis not relevant to this discussion.
Cheating? Creating a fake?
Hi-fi exists to create an artifice, an illusion. It's all a fake!
Precisely, Steve - and it's that point which Martin simply isn't getting.....
By using a well-designed high-quality, neutral sounding valve amplifier, which measures properly against all relevant test parameters (and there are many which qualify as such, using that criteria - the others don't interest me, as they'd never grace my system), you are no more 'deliberately adding distortion' to the signal than you are if you're using a transistor amp - all you're doing is adding a different type of distortion.
Therefore, at the end of the day, all you can do is choose your 'favourite flavour' of distortion, which no matter what that is, will likely make the amplifier that produced it no more 'accurate sounding' than another amplifier that produced a different type of distortion, which someone else preferred the 'flavour' of! :eyebrows:
We need to rid ourselves of the notion that simply because some transistor amplifiers measure better than some valve amplifiers, in certain areas, it automatically makes the former the more 'accurate' devices for reproducing music. Incidentally, the opposite also applies, in reference to valve amplifiers.
Quite simply, there is no genuinely 'more accurate' anything, when it comes to hi-fi systems reproducing recorded music. Like Steve says, it's ALL a fake of one type or another, so choose your favourite fake!
Hopefully, I won't have to repeat the above 60 times, throughout the remainder of the thread, before this sinks in ;)
Marco.
SteveTheShadow
12-10-2013, 15:43
Valves sound different to transistors
Transistors sound different to transistors
Valves sound different to valves.
Resistors sound different to resistors
Capacitors sound different to capacitors
Speakers sound different to speakers
DACs sound different to DACs
turntables sound different to turntables
And so it goes ad infinitum.
Which is the correct version of the original recording?
Answer? the one you like.
Yes it is! it's a 100% certainty! I will not back down on this as 40 years of experience, + repairing amps everyday + studying electronics for all this time + working for well known manufacturers + running my own business in amp repairs for many years has given me the knowledge and experience to be able to say with absolute certainty that I am right!!
End of!
Well, we'll just have to agree to disagree, sweetheart - END OF!! :ner:
The fact is, your experience to date, as valid as it is, doesn't qualify as scientific fact any more than mine does.
Marco.
The Grand Wazoo
12-10-2013, 15:45
Yeah - the reviewer preferred the valve version, if I remember correctly - which I'm pretty sure I do:)
You do.
Valves sound different to transistors
Transistors sound different to transistors
Valves sound different to valves.
Resistors sound different to resistors
Capacitors sound different to capacitors
Speakers sound different to speakers
DACs sound different to DACs
turntables sound different to turntables
And so it goes ad infinitum.
Which is the correct version of the original recording?
Answer? the one you like.
The end.;)
attempting to then enhance it by deliberately adding distortion in the amplification section just seems wrong to me.
Way to go, suggest I had suggested something, and then argue against it. Knock yourself out.
Does anyone remember TdP basically making the same amp (or as similar as possible) as a SS and a valve version, to prove there was, in fact, no audible difference?
Yep, it was a marketing masterstroke that he still makes great use of.
Yep, it was a marketing masterstroke that he still makes great use of.
LOL - indeed! :D
Marco.
Arkless Electronics
12-10-2013, 15:58
Well, we'll just have to agree to disagree, sweetheart - END OF!! :ner:
The fact is, your experience to date, as valid as it is, doesn't qualify as scientific fact any more than mine does.
Marco.
Ok if you won't believe what I'm telling you as a professional EE with experience of thousands of amplifiers then I suggest you try reading a load of textbooks on reliability in electronics equipment.... Oh I suppose they're all wrong as well because you have a couple of valve amps that have been reliable for you...
As you seem to consider yourself more knowledgeable than experts in their field I sincerely hope you don't get cancer as no doubt you'll consider the advice of your consultant to be bollocks as well !!
and moving on.....
Ok if you won't believe what I'm telling you as a professional EE with experience of thousands of amplifiers then I suggest you try reading a load of textbooks on reliability in electronics equipment.... Oh I suppose they're all wrong as well because you have a couple of valve amps that have been reliable for you...
As you seem to consider yourself more knowledgeable than experts in their field I sincerely hope you don't get cancer as no doubt you'll consider the advice of your consultant to be bollocks as well !!
and moving on.....
:rolleyes: :rolleyes:
That's complete bollocks logic. Quite simply, your status as an electronics engineer doesn't automatically make your experiences and discoveries in audio a 'scientific fact'. If you truly think that, then you have a rather inflated opinion of yourself!
Also in terms of my own attitude towards genuine experts in their field of expertise, medical or otherwise, what you've written is completely untrue.
It also doesn't take into consideration the extensive experience of other people here, in terms of their use of valve and transistor amplifiers, which supports my argument and my own experiences, so yes indeed, let's move on!!
Marco.
Valves sound different to transistors
Transistors sound different to transistors
Valves sound different to valves.
Resistors sound different to resistors
Capacitors sound different to capacitors
Speakers sound different to speakers
DACs sound different to DACs
turntables sound different to turntables
And so it goes ad infinitum.
Which is the correct version of the original recording?
Answer? the one you like.
Well, yes. The trouble is, some people won't stop at 'it's the sound I like', and insist that their system produces a more 'real', or more 'accurate' or more 'emotional' version of the recording.
anthonyTD
12-10-2013, 16:46
hi Martin,
If you really believe, and standby what you say below,
Then i seriously suggest that you stop listening to recorded music, because its all fake...;)
A...
Nick
To take your book/typeface analogy - what if I took a boring novel and re-wrote it in street slang? It would certainly be less dull to read but it would also be a lot further away from what the author intended. The musicians either convey their emotion through the music with varying degrees of success, and the entirety of their efforts are there on the recording - attempting to then enhance it by deliberately adding distortion in the amplification section just seems wrong to me. It's cheating, it's creating a fake and it's not in keeping with the basic principle of hi-fidelity.
hi Martin,
If you really believe, and standby what you say below,
Then i seriously suggest that you stop listening to recorded music, because its all fake...;)
A...
Then I want to hear the fake (or as close as possible) that the recording engineer wanted me to hear ;) BTW I am not suggesting for second that cannot be done with valve amplification so please don't infere that, anyone.
anthonyTD
12-10-2013, 17:05
Thats fine Martin,
I was only pulling your chain.:eek::lol::)
A...
Then I want to hear the fake (or as close as possible) that the recording engineer wanted me to hear ;) BTW I am not suggesting for second that cannot be done with valve amplification so please don't infere that, anyone.
Then I want to hear the fake (or as close as possible) that the recording engineer wanted me to hear
What he wanted you to hear or what he heard in the studio? They may not be the same thing.
BTW, I am not suggesting artificially breaking the sound either, but there is a lot more to it than a wire with gain.
anthonyTD
12-10-2013, 17:15
How many of us at some point have listened to a track or album, and thought, the engineer who mastered this must have been deaf...:lol:
A...
What he wanted you to hear or what he heard in the studio? They may not be the same thing.
BTW, I am not suggesting artificially breaking the sound either, but there is a lot more to it than a wire with gain.
Well, yes. The trouble is, some people won't stop at 'it's the sound I like', and insist that their system produces a more 'real', or more 'accurate' or more 'emotional' version of the recording.
That's most probably because some systems *do* make recorded music sound more real than others, but the sound produced can still never be genuinely accurate. However, the problem comes when attempting to PROVE, in an objective sense, which of the sounds produced is, in actuality, the most 'real' or 'accurate'! ;)
I prefer to use the term 'lifelike', as it gets a similar message across, but as its meaning is less precise than 'accurate', it is therefore less open to scrutiny. Creating a 'lifelike sound', for me, is the holy grail in any aspect of high-end audio.
Marco.
you mean men care what women think?:scratch:
They ought to - if they want to maximise the interaction.
Nick & Anthony
You are the double E's specialising in audio and I am just a punter whose knowledge does not extend further than O level physics and a city & guilds, both decades ago now. All I can do is work from first prinicples using experience and logic. Let me ask you this - would you place ultra-low noise and distortion at the top of your list when designing a power amplifier? If not, what would the priorities be?
What he wanted you to hear or what he heard in the studio? They may not be the same thing.
BTW, I am not suggesting artificially breaking the sound either, but there is a lot more to it than a wire with gain.
All I want to hear, as closely as possible, and with the least amount of introduced artifice, is the sound that left the studio, and which is contained in the CD or record that I've bought, whether that sound is good or bad. Simples! The music will then take care of itself.
For me, that is what high-fidelity audio is all about :)
Marco.
Arkless Electronics
12-10-2013, 17:34
:rolleyes: :rolleyes:
That's complete bollocks logic. Quite simply, your status as an electronics engineer doesn't automatically make your experiences and discoveries in audio a 'scientific fact'. If you think that, then you have a rather inflated opinion of yourself!
Also in terms of my own attitude towards genuine experts in their field of expertise, medical or otherwise, what you've written is completely untrue.
It also doesn't take into consideration the extensive experience of other people here, in terms of their use of valve and transistor amplifiers, which supports my argument and my own experiences, so yes indeed, let's move on!!
Marco.
I would have moved on but that is not only complete rubbish but also highly offensive.
I'm sure that on this matter being "debated" (electronics) folks can make up their own minds as whether the professional opinion of an Electronic Engineer or a picture framer is likely to be accurate.
anthonyTD
12-10-2013, 17:37
Hi Martin,
Speaking for my own priorities, yes indeed, i would design for low noise floor and low distortion,[i always do] but not to the extent that the end result was to strangle the life out of the music being portrayed...There is a fine balance to be adhered to as far as test measurements, and a piece of equipments ability to portray music with emotion, and soul
Nick & Anthony
A...
You are the double E's specialising in audio and I am just a punter whose knowledge does not extend further than O level physics and a city & guilds, both decades ago now. All I can do is work from first prinicples using experience and logic. Let me ask you this - would you place ultra-low noise and distortion at the top of your list when designing a power amplifier? If not, what would the priorities be?
anthonyTD
12-10-2013, 17:42
Jez,
Don't for one minute think your opinions here are not valued, as engineers,we are all in this together, however, we all have differences of opinion, that does not make for fact, just opinions.
A...
I would have moved on but that is not only complete rubbish but also highly offensive.
I'm sure that on this matter being "debated" (electronics) folks can make up their own minds as whether the professional opinion of an Electronic Engineer or a picture framer is likely to be accurate.
I would have moved on but that is not only complete rubbish but also highly offensive.
I'm sure that on this matter being "debated" (electronics) folks can make up their own minds as whether the professional opinion of an Electronic Engineer or a picture framer is likely to be accurate.
Trouble is, that's NOT what the argument is about. Are you being deliberately obtuse? :doh:
Are you seriously telling us that just because you're an electronics engineer, that your experiences to date in audio are thus automatically a scientific fact??
If so, then Anthony and Nick, as electronic engineers, can similarly rejoice in all theirs also being 'scientific facts' (although I doubt that they're be quite so arrogant as to think so)!!
Marco.
Jez,
Don't for one minute think your opinions here are not valued, as engineers,we are all in this together, however, we all have differences of opinion, that does not make for fact, just opinions.
A...
EXACTLY!!!! Now, Jez, let that fact penetrate into your rhino-thick skull.
Marco.
walpurgis
12-10-2013, 18:28
I'm a little mystified with some of the foregoing. How can hands on experience and empirical knowledge, no matter how convincing to the individual (and quite possibly right I should say), be regarded as scientific fact? It isn't!
Arkless Electronics
12-10-2013, 18:33
I have not and never would claim that my own opinions are intrinsically scientific fact. It's you Marco who have twisted my words on that one.
I do indeed say that solid state is, in the context of hifi equipment more reliable and that is a scientific fact. That is because it IS a scientific fact and not because I personally say it is. It is absolutely accepted by all and sundry. Just cos you personally have had little or no trouble with a few valve amps that you own does not prove in any way that valve amps are as reliable/more reliable than solid state. I am speaking not only from my own experience of having worked on thousands of amplifiers but also from everything I have learned from all the many hundreds of text books on electronics which I have read over the years and the views of the many, many fellow EE's I have worked with both in audio electronics and also many other areas of the subject including test and measurement and even military electronics. It is absolutely accepted wisdom in the industry and always has been. I was not giving an opinion but stating a fact.
This is why valves are not used in space craft, medical electronics, monitoring equipment in nuclear power stations etc
walpurgis
12-10-2013, 18:42
This is why valves are not used in space craft, medical electronics, monitoring equipment in nuclear power stations etc
Would that not be more down to cost and in the case of spacecraft, weight, size and power consumption (which are critical)?
cloth-ears
12-10-2013, 18:44
Putting aside the transistor verses valve reliability issue, another vital component which is common to both is the humble capacitor. The service life of a capacitor is expressed in hours/temperature. The hotter the environment the shorter the service life. That is a fact. Valve amplifiers run hotter for longer than their transistor counterparts. In my experience capacitor failure is a common reason for amplifier breakdowns.
hifi_dave
12-10-2013, 18:45
Rumour has it that valves are used in a lot of military equipment.
I have not and never would claim that my own opinions are intrinsically scientific fact. It's you Marco who have twisted my words on that one.
Then you're having difficulty expressing yourself, as it's not only me (but also Anthony) who've interpreted your comments in that way. I’m not twisting anything, simply responding to the words I see in front of me.
I do indeed say that solid state is, in the context of hifi equipment more reliable and that is a scientific fact. That is because it IS a scientific fact and not because I personally say it is.
How exactly is that a scientific fact? Show me where it says so. The scientific fact refers to the reliability of a transistor versus that of a valve, in isolation, not how the equipment either are used in performs afterwards, as a whole.
Others here, not only me, have reported the unreliability of some solid-state amplifiers and how they have blown output stages, and experienced all sorts of other failures, including documenting those failures in reference to valve amplifiers, which suggests to me that neither type of amplifier is infallible and that one of them can develop faults as easily as another, but for different reasons.
I see no irrefutable evidence (and as much as you like to think so, what you've experienced in your years as an EE doesn't qualify as such), which shows that a well-designed valve amplifier, fitted for example with the best NOS tubes, is automatically any less reliable than a well-designed transistor one.
In any case, I'm getting bored with this now, as the debate is becoming circular and we will simply never agree on the matter, so I'll bow out now from this particular part of the discussion and let you have the last word.
Marco.
Rumour has it that valves are used in a lot of military equipment.
Certainly old Soviet military equipment used valves rather than transistors - but that was because valves would largely survive the elecromagnetic pulse created by a nuclear explosion. Valves were used in some early NATO equipment, dating from the late forties.
I can assure you that modern military equipment is full of solid state componentry, especially integrated circuits which have been nuclear 'hardenend'. It is also true that valve circuitry is neither used in medical equipment, nor in any other safety-critical situation.
Rumour has it that valves are used in a lot of military equipment.
Indeed. ebay is awash with military spec NOS valves from the war era, used then in very critical military applications, which are coincidentally amongst the best sounding and most reliable valves you can buy today for audio use - I even use some of them in my own equipment! :)
Valves were also used at one time in the telecommunications industry, again I believe with great success.
I'm afraid that Jez's commercial prejudice against valves, as a designer of solid-state equipment, is shining through and clouding the reality!!
Marco.
Certainly old Soviet military equipment used valves rather than transistors - but that was because valves would largely survive the elecromagnetic pulse created by a nuclear explosion. Valves were used in some early NATO equipment, dating from the late forties.
I can assure you that modern military equipment is full of solid state componentry, especially integrated circuits which have been nuclear 'hardenend'. It is also true that valve circuitry is neither used in medical equipment, nor in any other safety-critical situation.
Gwan. You'll be telling us next that the military and the medical industry don't use 'special' cables or supports!
Certainly old Soviet military equipment used valves rather than transistors - but that was because valves would largely survive the elecromagnetic pulse created by a nuclear explosion. Valves were used in some early NATO equipment, dating from the late forties.
I can assure you that modern military equipment is full of solid state componentry, especially integrated circuits which have been nuclear 'hardenend'. It is also true that valve circuitry is neither used in medical equipment, nor in any other safety-critical situation.
Hi Barry,
Yup, but it doesn't mean that at one time valves didn't do just as good a job, in the context where they were used, and in terms of what was relevant at that time.
Marco.
Hi Barry,
Yup, but it doesn't mean that at one time valves didn't do just as good a job, in the context where they were used, and in terms of what was relevant at that time.
Marco.
Things move on and times change. No reason why a PROPERLY IMPLEMENTED (s'cuse caps) valve design can't last for decades of domestic use with original valves - EAR 509's use a output valve once common in televisions and used these BECAUSE of their long hard lives in their main domestic function! I'm sure the 'Copper' amps are way under-used to maintain reliable life.
having said the above, GOOD solid state amps should also last for decades. The fact that Naim run their caps to within an inch of their limits (excluding peaks) and are/were left on 24/7 doesn't mean ALL ss amps are going to be unreliable - look at all those Jap amps of the 70's which only now, after 40 years or so, are starting to suffer old age symptoms.......
I would place low noise as the first thing to worry about, and that covers a lot of things under the one banner of noise. I think low distortion is also important, but I think what is more important than low distortion in inself is controlling the type of distortion. I find that an amp that measures ok, but not great, that has 2nd harmonic at (say) -75dB below signal, 3rd at -90dB below signal, and all the higher harmonics at least below -120dB will sound much better than one where the 2nd is absent, 3rd is down at -90dB, and there is a spray of harmonics from 4th to 11th or above at -100dB and a lawn of intermod products of those higher harmonics. I also find amps that may have higher distortion, but a constant distortion spectra from 20Hz to 20kHz, many measure fine at 1k, but get up to 5k, and the harmonics start to arrive bringing intermod with them such that even though the harmonic is above audible, when music is playing, you get a wash of difference signals that reflect down into the audio band. I would also say that a amp that has improving distortion figures with reduced levels sounds better in real life than one that measures fine at full power. This of couse ties in with why I think low noise is so important.
But thats just my take on the subject.
hifi_dave
12-10-2013, 19:34
Certainly old Soviet military equipment used valves rather than transistors - but that was because valves would largely survive the elecromagnetic pulse created by a nuclear explosion. Valves were used in some early NATO equipment, dating from the late forties.
I can assure you that modern military equipment is full of solid state componentry, especially integrated circuits which have been nuclear 'hardenend'. It is also true that valve circuitry is neither used in medical equipment, nor in any other safety-critical situation.
Valves were used in Telecoms equipment until the 80's. As a Telecoms Technician, I worked on International equipment until then.
As for military equipment - a friend, who is now a Hi-Fi retailer in Israel, was for a couple of years, manning the Patriot missiles and launchers there. He was so excited to see the banks of valves inside these devices that he sent me a pic or two. Not sure that was allowed though ?
Gwan. You'll be telling us next that the military and the medical industry don't use 'special' cables or supports!
The military don't really use anything 'special', apart from being rugged and able to withstand rough handling, but some specialised (and very expensive) cables are used in space-borne applications. The same applies to the medical industry - though some cables used 'in vitro' have to be somewhat special. Cables used in nuclear safety-critical applications can be highly specialised, as they need to have a very low surface transfer impedance to be completely immune from EMI.
In most instances all these applications require the use of specialised connectors: you won't find any RCA phonos used (or come to think of it Cannon XLRs).
As for military equipment - a friend, who is now a Hi-Fi retailer in Israel, was for a couple of years, manning the Patriot missiles and launchers there. He was so excited to see the banks of valves inside these devices that he sent me a pic or two. Not sure that was allowed though ?
Wow - would love to see that pic! :eek:
Marco.
hifi_dave
12-10-2013, 19:47
Wow - would love to see that pic! :eek:
Marco.
It was when Sadam was sending Scuds into Israel every day. The Patriots were used to shoot them down before they did any damage. He also sent photos of Israelis in Cafes, in the streets and working with gas masks on. Business as usual was the message.
Wow - would love to see that pic! :eek:
Marco.
Nah - you want to see the banks of KT66 or 88s used in the amplifiers used to drive the equipment that tests items for survivability against vibration and shock (lots of "g"s, require lots of watts)
anthonyTD
12-10-2013, 19:52
So, from an engineering point of view, and from test measurements, can we as engineers agree on what types of distortions are the most objectionable as far as the audio frequency spectrum is concerned,ie; low order odds and evens, high order odds and evens, inter modulation,switching, etc, etc...
A...
Arkless Electronics
12-10-2013, 19:53
Valves were used in Telecoms equipment until the 80's. As a Telecoms Technician, I worked on International equipment until then.
As for military equipment - a friend, who is now a Hi-Fi retailer in Israel, was for a couple of years, manning the Patriot missiles and launchers there. He was so excited to see the banks of valves inside these devices that he sent me a pic or two. Not sure that was allowed though ?
Obviously valves were at one time used in applications where they have now been supplanted by SS. The transistor had to be invented before it could be used!
In some areas valved equipment continued to be used long after one would have expected it to be retired, purely on cost grounds. IE it still works so keep using it for now.... I find it highly doubtful that patriot missiles would use valves! I reckon your mate was pulling your leg.... Show the pictures please.
More generally, I'm certainly not saying that valved equipment is intrinsically unreliable. It can indeed be very reliable as we all know. It is however considerably less reliable than solid state equipment.
On that particular point of the thread I too will now bow out as I certainly didn't join in the thread in the first place in order to have an argument :)
Nah - you want to see the banks of KT66 or 88s used in the amplifiers used to drive the equipment that tests items for survivability against vibration and shock (lots of "g"s, require lots of watts)
Lol - BOTH pics would be great. I guess that if valves were being used in such critically important applications, especially when transistors were available to do a similar job, then they can't be that unreliable! ;)
Marco.
So, from an engineering point of view, and from test measurements, can we as engineers agree on what types of distortions are the most objectionable as far as the audio frequency spectrum is concerned,ie; low order odds and evens, high order odds and evens, inter modulation,switching, etc, etc...
A...
It's usually assumed that low order even harmonic distortion is less objectionable (even euphonic) to that of odd order. It is also thought that the ear will prefer a complete spectrum of harmonics, whose amplitude fall-off logarithmically with order (that is linearly on a dB scale). If any harmonics are 'missing' from the spectrum this will sound unpleasant.
Well that's the theory anyway. In practice musical instruments will often have a whole multitude of overtones, many of which are not harmonically related.
I'm sure distortion products produced by switching power supplies are thought to be bad.
Arkless Electronics
12-10-2013, 20:03
Valves were only used in shaker table amplifiers until suitable transistor amp became available. Again though, some of these were used into the 80's simply because they are an expensive piece of capital equipment and if the old valve one was still working ok it would likely be used until it became too expensive to maintain reliably. I remember seeing banks of KT88 based amplifiers in use in the Camerons brewery in Hartlepool around 1982 (I didn't ask what they were used for) but it's extremely unlikely that they would have remained in use much later than that.
Lol - BOTH pics would be great. I guess that if valves were being used in such critically important applications, especially when transistors were available to do a similar job, then they can't be that unreliable! ;)
Marco.
I think it was cheaper to do it with valves than with trannies.
Sure, but if that's the case it doesn't disprove or discredit their reliability.
Marco.
anthonyTD
12-10-2013, 20:13
My Dad was a service engineer from the 1950's on, and he always said' one of the worst and therefore one of the most unhealthy places to put a valve was in a color television!!!:eyebrows::lol:
Lets be honest, no one would want a valve TV, or even a valve radio for every day use these days, Transistors have revolutionized the way we live, and we must be very thankfull for them, however, they are not infallible, and they are not perfect, they do fail, and fail catastrophically in some cases, but on the whole, when you think of everything that contains them [and its a lot] that we take for granted every day, they are indeed very reliable...
A...
It's correct that the valves themselves are the weak part of a valve amp and many domestic amps over-drove them to get power cheaply. The Quad II's are a classic example of use for very long life, other bits inside often causing valve failure instead after twenty or more years.
kininigin
12-10-2013, 20:38
Interesting thread and read guys! I don't have much to add,other than i've gone down the valve pre/SS power route and this works very well for me,so it's been interesting hearing the pros and cons for each of the technologies!
It's correct that the valves themselves are the weak part of a valve amp and many domestic amps over-drove them to get power cheaply.
That is a VERY important point in the debate about reliability. Valve amplifier designs that are biased to over-drive valves, simply to get maximum power output, are fundamentally NOT in the equation as examples of premium reliability.
As you correctly say, one of the reasons why the Copper amp Anthony produces is so reliable (and I'm sure it's the same with Nick's designs) is because it's operating WELL WITHIN its electrical capabilities, and so no parts of the circuit are ever over-stressed.
That also applies to the output valves it uses, which are not being over-driven at any point (with a quad of KT120s at the helm, in P/P mode, 50W Class A power output is well within the design capabilities of those valves, not to mention the 500VA mains transformer fitted on the amp itself), and so all-in-all, the whole amplifier takes things in its stride, which in turn is why the music it reproduces sounds so 'effortless'! :)
Marco.
If you ask me if valves are reliable I'd simply say it depends, really, on who made the ^!&%ing things!
From experience:
Golden Dragon EL84s - bought 12 for a Beard amp - within 3 weeks half of them had heater faults.
JJ EL84s - good sounding, but not entirely reliable. 3 failures in a bunch of 12.
Tesla KT88s - sounded fantastic in an Air Tight - but the filaments kept breaking. Now EAT KT88s. I hope they've fixed the problem!
Very reliable:
Most NOS small signal valves from the likes of Mullard, Amperex, RCA etc
Tung Sol 6550.
Russian tubes - never had one with a fault or go on me.
Amperex, RCA, GE NOS 211s - not experienced any problems in years of usage with any of them. The RCAs were made in 1942. Cool. I feel sure I'll never wear them out.
SteveTheShadow
12-10-2013, 21:05
Just to go back to designing for low distortion. If you are designing a valve push-pull amplifier, and do not have a turntable, but you do have a DAC with balanced output, the best thing you can do for the sound of your amp is to ditch the phase splitter.
IME the phase splitter is the achilles heel of a valve PP amp. The improvement gained from ditching it is not subtle.
Most modern DACs have a balanced output on XLRs. Hardly anyone uses them, they don't know what they are missing.
I designed my latest PP valve amp to be fully balanced front to back, balanced shunt volume control, straight onto the grids of a push-pull driver stage, into push-pull output stage. Two stages, triode strapped output stage, no feedback.
But why stop at digital? Phono cartridges are just begging to be wired balanced and a balanced phono stage into a balanced, phase splitterless PP amp would give a mighty fine sound. Of that I'm sure.
Nick & Anthony
You are the double E's specialising in audio and I am just a punter whose knowledge does not extend further than O level physics and a city & guilds, both decades ago now. All I can do is work from first prinicples using experience and logic. Let me ask you this - would you place ultra-low noise and distortion at the top of your list when designing a power amplifier? If not, what would the priorities be?
Martin, now that you've had replies from both designers, what do you make of what they've said? :)
Marco.
P.S Good points there, Steve, particularly in reference to phono stages!
My Dad was a service engineer from the 1950's on, and he always said' one of the worst and therefore one of the most unhealthy places to put a valve was in a color television!!!:eyebrows::lol:
Lets be honest, no one would want a valve TV, or even a valve radio for every day use these days, Transistors have revolutionized the way we live, and we must be very thankfull for them, however, they are not infallible, and they are not perfect, they do fail, and fail catastrophically in some cases, but on the whole, when you think of everything that contains them [and its a lot] that we take for granted every day, they are indeed very reliable...
A...
Tell me about it! Valve tellies where very unreliable! I used to work on CRT computer terminals back in the eighties and quickly found HT plus SS just dont mix, LOL! My mate runs a TV repair business and valve TV's kept his business going for many many years, happily with the advent of SS, plasma and LCD things just got better! As they proved to be just as unreliable if not more so! :D
Martin, now that you've had replies from both designers, what do you make of what they've said? :)
Marco.
P.S Good points there, Steve, particularly in reference to phono stages!
Yes, thanks for your replies, Nick Anthony and Steve. It was interesting to note that both of you agreed that low noise was a major consideration. Anthony pointed out that to obsess over noise and distortion when designing the circuit may strangle the life from the music. Nick expanded on this with regards to the different types of distortion, and that they may be benign or not dependant on harmonic and the frequency. I could really ask questions about this all night but given these points is there really an inescapable trade off between banishing distortion at any harmonic or frequency and not killing the sound? And is low noise preferable to low distortion?
anthonyTD
12-10-2013, 21:32
Tis true,
Conventional phase splitters used in typical valve circuits, whether they be concertina, or long tailed pair are the main bug bear as far gaining a perfectly symmetrical drive for the push pull output stage, however, using modern components, ie; current sources, this is no longer an issue, of course things would have been much simpler if there had been a PNP valve...:eyebrows:
A...
Just to go back to designing for low distortion. If you are designing a valve push-pull amplifier, and do not have a turntable, but you do have a DAC with balanced output, the best thing you can do for the sound of your amp is to ditch the phase splitter.
IME the phase splitter is the achilles heel of a valve PP amp. The improvement gained from ditching it is not subtle.
Most modern DACs have a balanced output on XLRs. Hardly anyone uses them, they don't know what they are missing.
I designed my latest PP valve amp to be fully balanced front to back, balanced shunt volume control, straight onto the grids of a push-pull driver stage, into push-pull output stage. Two stages, triode strapped output stage, no feedback.
But why stop at digital? Phono cartridges are just begging to be wired balanced and a balanced phono stage into a balanced, phase splitterless PP amp would give a mighty fine sound. Of that I'm sure.
Just to go back to designing for low distortion. If you are designing a valve push-pull amplifier, and do not have a turntable, but you do have a DAC with balanced output, the best thing you can do for the sound of your amp is to ditch the phase splitter.
IME the phase splitter is the achilles heel of a valve PP amp. The improvement gained from ditching it is not subtle.
Most modern DACs have a balanced output on XLRs. Hardly anyone uses them, they don't know what they are missing.
I designed my latest PP valve amp to be fully balanced front to back, balanced shunt volume control, straight onto the grids of a push-pull driver stage, into push-pull output stage. Two stages, triode strapped output stage, no feedback.
But why stop at digital? Phono cartridges are just begging to be wired balanced and a balanced phono stage into a balanced, phase splitterless PP amp would give a mighty fine sound. Of that I'm sure.
Spot on Steve and I've heard the fruits of your work.....work! at the last Owston! I found a while back how important the phases splitter is in a valve PP amp and spent a quite a bit of effort in getting it linear in my designs but your solution of going balanced into the amp from the source is by far a better solution.
Tell me about it! Valve tellies where very unreliable! I used to work on CRT computer terminals back in the eighties and quickly found HT plus SS just dont mix, LOL! My mate runs a TV repair business and valve TV's kept his business going for many many years, happily with the advent of SS, plasma and LCD things just got better! As they proved to be just as unreliable if not more so! :D
I recall that transistorised tellys were pretty unreliable up until the early eighties. My old man always rented a top of the line set and we always had a repairman out about every six months or so throughout the Seventies. You took it for granted.
And before anyone says Sony Trinitron you couldn't rent one of them in the Seventies. Not in Liverpool anyway.
I recall that transistorised tellys were pretty unreliable up until the early eighties. My old man always rented a top of the line set and we always had a repairman out about every six months or so throughout the Seventies. You took it for granted.
And before anyone says Sony Trinitron you couldn't rent one of them in the Seventies. Not in Liverpool anyway.
Exactly, back in the seventies my Dad rented the TV and the visit from the repair man was a regular occurrence.
anthonyTD
12-10-2013, 21:54
Low noise floor is very important when trying to reproduce very small and delicate signals, the less you are modulating the amplifier with unwanted noise to start with, the better...AS far as designing for the lowest possible distortion, well, this will depend on the type of devices being used, as i have already stated in an earlier post [much earlier now] valves produce predominantly low order harmonic/distortion,Transistors have the potential to produce low order and much higher, so, it could be argued that it is more important to design for much lower over-all distortion in solid state designs than valve, as has been said again in this thread much earlier on, higher odd order harmonics are much more objectionable to our hearing, than low order types, even in small quantities,this is one of the reasons it was common to see transistor amplifiers advertised in the 1970,s and 80's with .0000000001% distortion figures. One of the most common ways of achieving these low distortion figures was the use of feedback,now in solid state designs, it is possible to use a lot more feedback then with conventional valve designs using output transformers, which was very convenient as far as test figures were concerned, however, it was soon realized that excessive use of feedback is not a good thing, and tended to strangle the life out of the music etc.
A...
Yes, thanks for your replies, Nick Anthony and Steve. It was interesting to note that both of you agreed that low noise was a major consideration. Anthony pointed out that to obsess over noise and distortion when designing the circuit may strangle the life from the music. Nick expanded on this with regards to the different types of distortion, and that they may be benign or not Dependant on harmonic and the frequency. I could really ask questions about this all night but given these points is there really an inescapable trade off between banishing distortion at any harmonic or frequency and not killing the sound? And is low noise preferable to low distortion>
anthonyTD
12-10-2013, 21:59
We had a big old philips transistor color tv in the 70's, and the back was off permanently, it went wrong that often...
A..
Exactly, back in the seventies my Dad rented the TV and the visit from the repair man was a regular occurrence.
Do we understand why too much feedback degrades the sound when in theory it should improve it by lowering distortion? Does it create noise in the circuit? As I said I could ask all night I'll leave you alone after this :)
I recall that transistorised tellys were pretty unreliable up until the early eighties. My old man always rented a top of the line set and we always had a repairman out about every six months or so throughout the Seventies. You took it for granted.
And before anyone says Sony Trinitron you couldn't rent one of them in the Seventies. Not in Liverpool anyway.
I remember valve TVs, but I think we always bought ours outright (as we did with everything else), from department stores - can't remember anything ever being rented.
We've still got a 24" Sony CRT TV, which produces a fantastically sharp and natural looking picture - and it'll be staying with us until its dying breath before we adulterate the lounge in our 19th century lodge with a plasma or LCD abomination! :exactly:
Marco.
I remember valve TVs, but I think we always bought ours outright (as we did with everything else), from department stores - can't remember anything ever being rented.
We've still got a 24" Sony CRT TV, which produces a fantastically sharp and natural looking picture - and it'll be staying with us until its dying breath before we adulterate the lounge in our 19th century lodge with a plasma or LCD abomination! :exactly:
Marco.
You were well off then, telly's were very expensive back then. I sort of know where you are coming from with the old Sony but seriously - stick it in the bedroom and get yourself a 50 inch plasma. You know where you will appreciate it most? (And everyone I know says the same thing) - Watching the footie. In HD. And I know you like yer footie ;)
Lol - trust me, if you ever come to visit, you'll realise why a 50" TV of any description would look ridiculous in our lounge amongst antique furniture and pottery, and various period-style nick-nacks! :eek:
Besides, as long as we own the house, the main feature of the lounge will always be our lovely inglenook fireplace (with Celestion 66s perched at either end), not some plastic mass-produced electronic monstrosity!! ;)
Marco.
anthonyTD
12-10-2013, 22:34
Way past my bedtime now martin,
If someone hasn't already picked up on this and answered by tomorrow, i will come back to it, in the meantime, think of a car with soft shock absorbers, and one with shocks that are too hard... somewhere in the middle is the perfect ride...
Its not an exact analogy by far, but its all your going to get from me tonight...;)
A...
Do we understand why too much feedback degrades the sound when in theory it should improve it by lowering distortion? Does it create noise in the circuit? As I said I could ask all night I'll leave you alone after this :)
I suspect that the large levels of feedback present in most (if not all) solid-state amplifiers (and the subsequent 'strangling effect' on music reproduced) is the main reason for them creating the anodyne sound I referred to earlier, in comparison with that produced by amplifiers containing more linear devices, which do not require 'controlling' in that way...
Marco.
Arkless Electronics
13-10-2013, 00:42
Tis true,
Conventional phase splitters used in typical valve circuits, whether they be concertina, or long tailed pair are the main bug bear as far gaining a perfectly symmetrical drive for the push pull output stage, however, using modern components, ie; current sources, this is no longer an issue, of course things would have been much simpler if there had been a PNP valve...:eyebrows:
A...
Ohh yes! How I agree with that!
PNP valves (as I mentioned about 50 posts ago)... we can dream!
Arkless Electronics
13-10-2013, 00:53
I'm working on a solid state phono stage (with possible off-shoots to line level amps and power amps) at the moment which carries on from the work of Owen Jones, Malcolm Hawksford and Joachim Gerhard and which if early results are anything to go by will have around 0.005% THD with ZERO FEEDBACK! Early days yet.. WIP... but watch this space ;)
Ps low levels of NFB can actually help create higher levels of odd order harmonic distortion! :eyebrows:
Oldpinkman
13-10-2013, 07:14
I suspect that the large levels of feedback present in most (if not all) solid-state amplifiers (and the subsequent 'strangling effect' on music reproduced) is the main reason for them creating the anodyne sound I referred to earlier, in comparison with that produced by amplifiers containing more linear devices, which do not require 'controlling' in that way...
Marco.
Are none of the engineers going to challenge that assumption that valves are more linear than trannies? :scratch:
Oldpinkman
13-10-2013, 07:26
I haven't had a chance to read this thread properly, not helped by the distraction with reliability. Has anybody discussed power amp output impedance and effect on bass lift with real speaker loads, and if so which post starts me off with that? (Stuff going on - hope to have a proper read later) :(
cloth-ears
13-10-2013, 07:41
One attribute of valve amplifiers often overlooked is their uncanny ability to suck common sense out of any room.
Common sense: The basic ability to perceive, understand, and judge things which is shared by ("common to") nearly all people, and can be reasonably expected of nearly all people without any need for debate
:mental:
Oldpinkman
13-10-2013, 07:41
That is a VERY important point in the debate about reliability. Valve amplifier designs that are biased to over-drive valves, simply to get maximum power output, are fundamentally NOT in the equation as examples of premium reliability.
As you correctly say, one of the reasons why the Copper amp Anthony produces is so reliable (and I'm sure it's the same with Nick's designs) is because it's operating WELL WITHIN its electrical capabilities, and so no parts of the circuit are ever over-stressed.
That also applies to the output valves it uses, which are not being over-driven at any point (with a quad of KT120s at the helm, in P/P mode, 50W Class A power output is well within the design capabilities of those valves, not to mention the 500VA mains transformer fitted on the amp itself), and so all-in-all, the whole amplifier takes things in its stride, which in turn is why the music it reproduces sounds so 'effortless'! :)
Marco.
That'll be the debate that was finished 12 pages earlier then...:doh:
Who gives a f&^% about assessing reliability beyond "fit for purpose". I'm interested in why more "proper" valve amps sound attractive than many solid state amps. :(
Oldpinkman
13-10-2013, 08:54
One attribute of valve amplifiers often overlooked is their uncanny ability to suck common sense out of any room.
Common sense: The basic ability to perceive, understand, and judge things which is shared by ("common to") nearly all people, and can be reasonably expected of nearly all people without any need for debate
:mental:
Oh it clearly polarises opinions. And this was your thread really, so maybe you can answer one of my questions. Why does a valve amp (good valve amp - properly designed) sound like a valve amp? I first asked Owen this question 25 years ago regarding why the Pip sounds "valvey" - not warm or lush or "bad valve" but lacking the "sterility" of the SS we were using. In particular - referenced against the Quad 44 which was our house pre-amp at the time. The phono difference is down to the transconductance RIAA circuit, but the line stage also sounds "refined" "smooth"
The "piss off and leave me alone" answer I got then (along with a circuit board for his "lecture" amp), was that it was to do with circuit topology. you can only use valves in a circuit in a more limited way than a transistor can be used and if you build a circuit with transistors like a valve circuit it will sound the same. It is not the sound of the device but the circuit topology. I never got the "lecture" to work before it was nicked back off me :(
On a beach in Norfolk earlier this year I tried to pick up from there, and we went off on some wild tangent (the problem being he starts an explanation, and we need a 4 hour detour to the ladybird book of electronics for me to understand his first point). I am promised an answer, but it could take a long time. I think, given the discussion we had, it is to do with feedback, and trying to minimise its use at certain key points in the circuit. Certainly that would fit with his description of what he wants to do with a power amp.
This question has been bugging me for 25 years now - and I hoped this thread might shine a bit of light. Owen's a nice guy, but he tends to speak pure maths. At least, it seems that way to a numpty like me.
So - why doesn't the Pip sound SS?????:scratch:
SteveTheShadow
13-10-2013, 09:12
Oh it clearly polarises opinions.
This question has been bugging me for 25 years now - and I hoped this thread might shine a bit of light.
So - why doesn't the Pip sound SS?????:scratch:
It only polarises opinions when a few people decide to be awkward.
Threads like this serve no purpose unless discussion is kept on track.
The question of why the pip sounds/sounded as good as it did is very simple to answer.
The late Paul Benson's theory that 99% of all hi-fi is crap answers it perfectly.
the Pip was in the 1% that doesn't.
That'll be the debate that was finished 12 pages earlier then...:doh:
Who gives a f&^% about assessing reliability beyond "fit for purpose". I'm interested in why more "proper" valve amps sound attractive than many solid state amps. :(
Well, why not direct your question at one of the resident engineers here, instead of moaning like a girl, who incidentally ALL produce solid-state equipment, commercially (yes, even Anthony and Nick!) ;)
Marco.
It only polarises opinions when a few people decide to be awkward.
Threads like this serve no purpose unless discussion is kept on track.
The question of why the pip sounds/sounded as good as it did is very simple to answer.
The late Paul Benson's theory that 99% of all hi-fi is crap answers it perfectly.
Though opinions vary widely about which products are in that 99%!
Are none of the engineers going to challenge that assumption that valves are more linear than trannies? :scratch:
I believe it is a measurable fact, although stand to be corrected. It is why, for example, that Anthony uses high-power FETs in all of his solid-state amplifier designs, because FETs are the silicon world's closest offering to the vacuum tube.
Short, but interesting discussion here: http://www.hifiwigwam.com/showthread.php?46554-Tube-Distinctions-v-ARC-Ref2-MkII-pre-amp
It also shows how Audio Research (a supposedly respected high-end valve equipment manufacturer) gives such equipment a bad name - especially in terms of reliability. Thankfully, not all valve gear is like that...
Marco.
cloth-ears
13-10-2013, 09:31
Oh it clearly polarises opinions. And this was your thread really, so maybe you can answer one of my questions. Why does a valve amp (good valve amp - properly designed) sound like a valve amp? I first asked Owen this question 25 years ago regarding why the Pip sounds "valvey" - not warm or lush or "bad valve" but lacking the "sterility" of the SS we were using. In particular - referenced against the Quad 44 which was our house pre-amp at the time. The phono difference is down to the transconductance RIAA circuit, but the line stage also sounds "refined" "smooth"
The "piss off and leave me alone" answer I got then (along with a circuit board for his "lecture" amp), was that it was to do with circuit topology. you can only use valves in a circuit in a more limited way than a transistor can be used and if you build a circuit with transistors like a valve circuit it will sound the same. It is not the sound of the device but the circuit topology. I never got the "lecture" to work before it was nicked back off me :(
On a beach in Norfolk earlier this year I tried to pick up from there, and we went off on some wild tangent (the problem being he starts an explanation, and we need a 4 hour detour to the ladybird book of electronics for me to understand his first point). I am promised an answer, but it could take a long time. I think, given the discussion we had, it is to do with feedback, and trying to minimise its use at certain key points in the circuit. Certainly that would fit with his description of what he wants to do with a power amp.
This question has been bugging me for 25 years now - and I hoped this thread might shine a bit of light. Owen's a nice guy, but he tends to speak pure maths. At least, it seems that way to a numpty like me.
So - why doesn't the Pip sound SS?????:scratch:
The one way to make an SS amp sound more like a valve amp is to drive the output through a transformer. Maybe the saturation of the coils adds a valve like sound or the much lowered damping factor removes the appearance feedback correction. I have tried this and it does work.
Are none of the engineers going to challenge that assumption that valves are more linear than trannies?
Unlikely, as other than some newer devices Nelson has been playing with, its measurably true that most valves are more linear than any transistor. The advantage transistors have is multiple (simply put and ignoring the problems), they are available in complementary pairs, and they are small cheap and low maintenance. So you can pack many more together and produce a composite device with huge gain and then use negative feedback loop(s) to linearise the result.
...plus they use lower voltages (easier to implement power supply) and produce far less heat.
...plus they use lower voltages (easier to implement power supply) and produce far less heat.
Not sure about the bit in brackets, but yep :-)
The advantage transistors have is multiple (simply put and ignoring the problems), they are available in complementary pairs, and they are small cheap and low maintenance. So you can pack many more together and produce a composite device with huge gain and then use negative feedback loop(s) to linearise the result.
It's interesting having dual-mono variable feedback adjustment pots on the Copper amp... Apart from being able to fine-tune how the amplifier 'behaves' and controls the speakers, thus optimising the sound, it doesn't half teach you about the positive and negative aspects of applying too much or too little feedback!!
The results obtained were certainly a learning curve for me ;)
Marco.
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