Printable View
HI ALL,
it was felt by some that this subject needed to be explored further and explained in more detail, so after thinking about it, and writing a lot, i decided that it would be better to start this thread off with an invitation for you guys to to tell us what amplification your using, ie, valve, or solid state, and what it is about your choice that works for you. hopefully this way it will start the thread off in good spirit, so without further a do lets get things started...:)
anthony,TD...
Dear Mr Matthews,
I've got this rather old 30W Copper valve amp thingy that I found behind my sofa amongst some stale Jaffa cakes and a half-eaten muffin. It sounds rather good though and appears to outperform a pair of 200W solid-state monoblocks I also own. Could you explain what's going on?
Yours in astonishment,
Hilda.
I use a power amp fitted with unobtanium V-FETs. Warm and sizeable bottom, solid and round front.
ok mr scotyital smarty pants,:eyebrows:Quote:
Originally Posted by Marco
here are some of the reasons and observations that are shared by many [including me] for reverting back to valves for audio.
Valve amplifiers be it single ended or push-pull, have long been thought of by many as superior beasts to solid state…whether their use be musical instrument related, or purely for audio replay, but what is it that still makes them more desirable to a growing number of musicians and audiophiles world wide than often the best of what solid state has to offer?
Well, here are some positive reasons. First off, valve designs produce predominantly low order harmonics (which is musically related); while solid state designs generally produce a full range of harmonic distortion, including the objectionable high order harmonics. This is due to a number of factors, including the transformer output of valve designs, and the large amounts of negative (electronic) feedback required in solid state designs, in comparison, valve designs need very little negative feedback, and some good sounding amps don't use any at all!
Circuit design undoubtedly plays an important role, valve circuits are often less complex and laid out differently, therefore It can be argued that simplicity is usually best, as the length and complexity can change the inductance and capacitance of a circuit. A more complex circuit will have a more complex sonic distortion characteristic. Minimalist single ended valve amps for example typically have a dominant very simple harmonic distortion spectrum. Complex modern transistor designs often have low level but extremely complex harmonic distortion spectra.
Another advantage of most valve amplifier designs is the high input impedance typically 100k in modern designs and as much as 1 Meg ohm in classic designs. By contrast, solid state amplifiers may have much lower input impedances, some as low as 20k This implies that it requires more energy to excite the input of a typical transistor amplifier to any given voltage than it does a typical valve amplifier. If sensitivity to small signals is a significant goal, then valve designs will typically outperform transistor designs.
Valve amplifiers in general do not need to use as much negative feedback as transistor amplifiers, and while some will argue [and rightly so in some cases] that the absence of negative feedback slightly increases harmonic distortion, by limiting the amount of negative feedback, it avoids instability, as well as slew rate and bandwidth limitations imposed by dominant-pole compensation in transistor amplifiers.
Valves versus transistors when driven hard distort quite differently, and it is well known and documented that valves clip more softly than transistors therefore allowing higher levels of distortion to be tolerated whilst still being able to portray the complex harmonic structure of for example a musical instrument..
i await your constructive comments.
anthony,TD...
I used to to think Valve amps were for the wolley jumper and slippers brigrade great mid but no bass and dynamics I went through many Solid state amps and would not even think about a valve amp.
Now I have a SAC Glowmaster it has more controlled bass, dyamics detail and larger soundstage than my old Gamut D200 MK3 but only is rated at 66watts I do not really understand this
Also I read it encourages something called 2nd Harmonics which are very pleasing to the ear; is this artical warmth or ? As the music sounds natural to me
hi john,Quote:
Originally Posted by John
its good to hear that all the perceived negative traits you mention above about your earlier informed but rather misguided view of valve amplifiers have now been put to rest, the more people i speak with who have recently converted to valves have similar stories to tell, so your far from alone in your experiences.
as for your confusion about the diffrence in percieved power ie, valve amplifiers seemingly having more power than an equaly matched watt for watt solid state amp, well i have my views on that too, but i would rather hold fire and give some of the other guys a chance to give their views on this for the moment.
anthony,TD...
Here's an interesting point to think about.
I have found that the earthing scheme of an amp can have a huge impact on the quality of its sound, not just hum and earth loops.
Almost all solid state amps are PCB based, almost all valve amps are hard wired.
A hard wired amp will tend to have much thicker (lower impedance) earth wiring compared to the tracks of a pcb.
I used valve amps for 15 years, and currently have a CA 740 not because i prefer solid state' its just i don't have the finances for a quality valve set up' i got the CA for a bargain price.
I did have a concordant valve pre with Audio Innovations 2nd audio mono(2a3) with border patrol psu's which was just wonderful it just sounded so big and there if you know what i mean, one point i would make regarding valve amps is that some like the 2nd audio's used solid state rectifiers, which caused the amp to sound loose and flabby with complex music' so when looking at valve amps' valve rectified choke smoothing is a must .
I just want a cheap as chips fully balanced valve pre which will drive two balanced outputs, and a few very powerful fully balanced valve power amps capable of driving difficult loads with lots of output 300w - 600w) and silent operation with 103db speakers, none of that background hiss or hum please, oh and bass must be proper, not that overblown under damped bass which people thinks sounds better.
By cheap as chips I mean comparable in price to a Yamaha E800 processor (silent) driving a brace of Alesis RA-500 bridged amps.
Cheers..
I agree with all of the above. :)Quote:
Originally Posted by anthonyTD
My own preference is to start with the most linear amplifying device possible, the triode and build amplifiers around that. That way we need to apply less of a band aid - negative feedback. The poor linearity of transistors means that circuit complexity increases, with feedback being almost mandatory and I believe this is a large factor in the sound.
When I built my 801A amp, as designed it had 2-3dB NFB, but, when I diconnected this sound quality improved. With NFB is sounded very clean and colourless, but without, all the timbre a vitality can back. It wasn't all positive and the bass became somewhat looser, but to me the trade off was well worth it.
I also agree that the spectrum of THD matters a lot as well as the absolute level, with low even order being preferred. Nelson Pass has done some ineteresting work there with the F1 & F2 designs , with one being PP and one being SE, thus having different distortion spectrums and different 'flavours'. I recently heard an F3 and it was very, very good indeed - sweet and grainless, a good alternativer for those who would like a SET, but don't want valves. Mind you, it's still hot and low powered. ;)
Sorry for the brain dump!
HI Anthony TD
I could not have said it any better....Quote:
Valve amplifiers be it single ended or push-pull, have long been thought of by many as superior beasts to solid state…whether their use be musical instrument related, or purely for audio replay, but what is it that still makes them more desirable to a growing number of musicians and audiophiles world wide than often the best of what solid state has to offer?
Well, here are some positive reasons. First off, valve designs produce predominantly low order harmonics (which is musically related); while solid state designs generally produce a full range of harmonic distortion, including the objectionable high order harmonics. This is due to a number of factors, including the transformer output of valve designs, and the large amounts of negative (electronic) feedback required in solid state designs, in comparison, valve designs need very little negative feedback, and some good sounding amps don't use any at all!
Circuit design undoubtedly plays an important role, valve circuits are often less complex and laid out differently, therefore It can be argued that simplicity is usually best, as the length and complexity can change the inductance and capacitance of a circuit. A more complex circuit will have a more complex sonic distortion characteristic. Minimalist single ended valve amps for example typically have a dominant very simple harmonic distortion spectrum. Complex modern transistor designs often have low level but extremely complex harmonic distortion spectra.
Another advantage of most valve amplifier designs is the high input impedance typically 100k in modern designs and as much as 1 Meg ohm in classic designs. By contrast, solid state amplifiers may have much lower input impedances, some as low as 20k This implies that it requires more energy to excite the input of a typical transistor amplifier to any given voltage than it does a typical valve amplifier. If sensitivity to small signals is a significant goal, then valve designs will typically outperform transistor designs.
Valve amplifiers in general do not need to use as much negative feedback as transistor amplifiers, and while some will argue [and rightly so in some cases] that the absence of negative feedback slightly increases harmonic distortion, by limiting the amount of negative feedback, it avoids instability, as well as slew rate and bandwidth limitations imposed by dominant-pole compensation in transistor amplifiers.
Valves versus transistors when driven hard distort quite differently, and it is well known and documented that valves clip more softly than transistors therefore allowing higher levels of distortion to be tolerated whilst still being able to portray the complex harmonic structure of for example a musical instrument..
And there is also ........
http://i549.photobucket.com/albums/i...omehi-f-15.jpg
http://i549.photobucket.com/albums/i...omehi-f-10.jpg
EQUATION Sound + Looks = :band: :surf:=NATURAL MUSIC..... and results in :):):):):mex:
Regards D S D L-----Neil :)
I have six amps at the moment,five of which are valve.The sand amp is an old wooden sleeved Sugden a21.Nice little amp,but cannot compete with the valve amps to my ears.I have two PP amps,both WAD kit jobbies-the KEL84 and an original WAD 300b.The single ended amps are a DIY copy of the old WAD 4watt SE,a Mr Liang 845 se and finally an Audioromy 813 se.On my system,the 813 easily sounds the best,probably partly to do witht the fact that my statics need a bit of power,and the 813 outputs a claimed 45 watts.
One thing with valve amps is that not only do you have the valves versus transistors thing,you get a further split with SE and PP.I do own two PP amps,but have to say I ultimately prefer SE.It just seems to have a naturalness and magic that PP cannot equal.I have read in the past that the distortion produced by DHT's in general quite closely matches the distortion characteristics of the human ear,which may explain why many prefer the way such amps sound,making them sound more "real" to human ears.Even Marco was impressed with the 813! The 813 is a directly heated tetrode,and in the amp I have they are wired in triode mode,and it does sound like a DHT in many ways.I've been told that the 813 is Andy Grove's (designer of many Audio Note and WAD amps amongst others) favourite valve and I can see why.Next step for me is to build a copy of Nick Gorham's 211 A2 amp,but using the 813,as if this cheapie chinese amp can sound so good,a proper design with top-rank components and transformers should sound sublime!
Is 'sand' just another term for solid state?
Yes,sorry,it refers to the silicon used in transistors,hence "sand".Just a colloquial expression commonly used by valve amp afficionados.
hi ali,Quote:
Originally Posted by Ali Tait
the diffrence as you quite rightly acknowledged between push-pull and single ended is quite distinct, and one of the reasons put forward for this is, push-pull output stages predominently cancel out even harmonics, and thus can to a degree reduce the natural 2nd and higher even harmonics found in the original music being re-produced, single ended on the other hand does not have this cancelation effect on the even harmonics, and hence they tend to sound more natural to the human ear. but with both technologies there are trade off's and in both the problem of odd harmonics still need to be addressed... feedback is unfortunetly a necesary evil in controling un-wanted harmonics that were not present in the original signal, and also used properly it can and is used for reducing the output impedence of the amp, making it more suitable for controling cone movements of the loudspeaker.
anthony,TD...
Agreed Antony,what you say is quite correct.However it's not an issue for me as I use 'statics.Both the PP amps I have are superb sounding.The KEL84 is a true giant-killer (like Stan's DAC!) and a superbly musical amp.I would say it would walk all over anything commercial up to a couple of grand,possibly quite a lot more,and the 300b PP is a superb amp too,and quite a no-compromise design with intestage transformers etc.
However,subjectively to my ears PP amps often sound muddled and flat in the midrange compared to SE.I can see how many would prefer the generally greater authority in the bass you get from PP(on conventional speakers for the reasons you stated),but that's not a real priority for me.It's that indefinable magic that you only seem to get from a good SE amp that wins my heart every time.Nothing I've heard to date beats it.As I've said before,I use valves because they sound better than anything else.If I came across a sand amp that sounded better,I'd use it.Valves are not the most user friendly things!
"To date" is the key phrase there, I feel.Quote:
It's that indefinable magic that you only seem to get from a good SE amp that wins my heart every time.Nothing I've heard to date beats it.
It'll be interesting to see what you make of the Copper amp in my system, Ali (bring your SETs along to compare). The Spendors are valve-friendly. I know exactly what you mean, but to my ears Anthony's Copper amp gives the best of both worlds and thus has quite a beguiling and spell-binding way with all types of music. "All types" is also another key phrase here ;)
One should never say never in hi-fi, and I certainly don't either with SE...
Marco.
PP output stages self cancel 2nd harmonics generated in the o/p stage only...they don't cancel out 2nd harmonics generated by the input or driver stage...as those harmonics are now part of the signal.Quote:
Originally Posted by anthonyTD
LOL I figured that was it - but what of germanium transistors ;)Quote:
Originally Posted by Ali Tait
That would be a 'flower amp'... :eyebrows:
Don't go casting nasturtions Mike :lol: :ner:
Ouch! :doh:
It's a bit of a thorny one, I'll give you that ;)
Groan! Marco,trust me,the 813 will play any type of music well.Remember the zep at Owston?
Ok, here goes...
I have been a guitar player for more than 40 years and I have never owned and would never own a solid state amp. In that endeavor, the attraction is clear: The manner in which valve amps clip is goooood. It even adds to the tactile experience of playing. With a small amp in a medium room, you can get the volume right on the cusp of heavy clipping and actually go from "clean" to "crunch" just by attacking the strings harder. You can take the next step, into creamy, sustained overdrive, with a bit of a boost of the guitar's volume control. Good stuff.
But theoretically, while all of that is wonderful for amping an electric guitar, it is less desireable in hifi, where we don't want pleasing harmonic distortion but no distortion. And, theoretically, the best way to reduce clipping, given good design in the first place, is to increase headroom. This can be done with valves, but two to three hundred watts per channel is an expensive proposition in a valve amp, and if the objective is to eliminate clipping - pleasant or otherwise - what would be the point?
Theoretically.
Fortunately, being primarily a headphone listener, I been able to test the theory at relatively little expense. A few hundred milliwatts, even into the difficult load of my Sennheisers, is a massive amount of headroom. Even at very high listening levels, clipping is not an issue. I've tried a few valve headphone amps through here for testing, and I've been very fortunate in that I've been able to keep them in my house for weeks, rather than listening to them in a store for a few minutes. The last, and one of the best, was 500 milliwatts, all valves, all point to point wired, lovely to look at and listen to. It would drive my Senns beautifully with so little of its volume control engaged, it breathed so easily under the weight of their 300 ohm, legendarily inconsistent load, that I'm as certain as I can be (without ABX testing :)) that it was not clipping. Was there still a touch of audible harmonic distortion in there? I don't know, but there was something. And it was something pleasant. I almost kept that one. But after two weeks of listening to it exclusively, I went back to my headphone reference -- an old (bought new in about '72), dual mono, mosfet Harman Kardon integrated amp with a headphone jack that is just insanely good. I went back and forth and listened to some very well-recorded music I'm very familiar with and there was a difference. To put it all in positive terms, which isn't hard, the valve amp had a sweetness that was very attractive, the old SS had a speed of response and a sense of control that lent an open clarity to the presentation.
But it was a very subtle gap. I would have loved to have kept both, but in the end, I decided that the difference between them was too slight and it wasn't worth the investment, even though it was small. And those were, in my view, ideal conditions for the valves. 30 to 60 watt valve amps driving conventional speakers with conventional efficiency? It has its charms, but I remain unconvinced that it is anything I would describe as superior. Attractive clipping is still clipping. I'd rather keep it away from cymbals, voices, etc.
Then, there is digital amplification....
Tim
Aye but the thing is Tim,Directly-Heated Triodes are the most linear amplifying devices ever constructed by Man.If distortion is the only story,how come a single-ended amp sounds so much better with no feedback than with,when with no feedback distortion is much higher?
Groan? LOL! Ali, I was referring to low-powered SET amps and small speakers, which I find somewhat restrictive - you've got neither, in fact your amp has got serious balls! :eyebrows:Quote:
Originally Posted by Ali Tait
Marco.
:lolsign: The groan was for the terrible puns in the previous few posts!
Ah, oi sees... :eyebrows:
I shall get my teeth more into this rather intriguing discussion later, particularly Tim's last post ;)
Marco.
hi Tim,Quote:
Originally Posted by tfarney
i agree to a point, but the whole reason i started this thread was to get some constructive comments from people who own both valve and solid state amps, it was not as your post seems to indicate meant to just "big up" one technolgy over the other, i have been involved with both types of amp topologies a long time now, and i know that both technologies when done right can sound exceptionaly good, but what i have put forward here is a start concerning some of the main diffrences that people can relate to, i did not and do not condone clipping in any form in hi fi aplications, and i agree, to avoid it in both designs you need a lot of headroom, but with transistor amplifiers the onset of clipping is so brutal that distortion aspects become all to clear instantly, why valve amps win in my opinion on this score is because when they get near to clipping [or maximum dynamic range]they self compress/limit to a degree and therefore the higher order harmonics that would be present in solid state that are objectionable at the onset of clipping are not present...
this i suspect is the reason why most people who have lived with both technolgies find that to get the same percieved power and sound stage that they get from valve amps you would need a solid state amp with a power output of up to ten times higher.:)
anthony,TD...
I don't think distortion is the only thing, nor do I think that SS is inherently superior. I have discovered though, that for me, when the two are both very well done, the difference is small enough and subjective enough that I wouldn't spend a whole lot more for one over the other.Quote:
Originally Posted by Ali Tait
Tim
With valve amps distortion figures generally dont go below 0.1% at normal levels into real loads. I get the impression (maybe Anthony can confirm/deny) that engineers designing valve amps dont waste a lot of time trying to reduce disortion further. However SS amps can go very low - 0.001%. To get such low level a huge amount of time has to be spent.
Is time spent reducing distortion at the expense of other areas??
hi paul,Quote:
Originally Posted by Primalsea
distortion figures are an inportant factor when designing both valve and solid state, but as discussed it is the type of distortion and its affects on the listener that has to be considered, ie, most conventional solid state designs are of a pushpull nature, hence it is important to try and design out or control any form of distortion to avoid creating the destructive higher order harmonics of which even small amounts are very objectionable. on the other end of the scale for eg a single ended directly heated triode valve amp output stage produces predominantly low order even harmonics, so quite large amounts of this type of distortion can be tolerated [as high as 10%] compared to conventional solid state, hence the need for correcting this type of distortion is much lower, thus the circuit can be designed much simpler and purer.
anthony,TD...
I made the mistake, two years ago, of buying a Chinese 300B single ended amplifier. It sounded absolutely wonderful for a year and a bit. In 1998 I owned a ready built WAD 300B PP amplifier and a KLP1 preamp. It was the finest amplifier I have ever heard. I have heard comparable transistor amplifiers in money terms but not one of them has had anywhere near the 'air' and 'space' of the valve amps. I adore valve amps but have always found that, when I've owned them, for some mysterious reason, I've always been glad to see the back of them. Coming bang up to date... I doubt that I shall ever again be in a position to spend two thousand pounds on an amplifier. In fact, I doubt I shall ever be a position to spend that amount of money on a complete system... I'm working on it though.
I think this is one of those cases where the cure (negative feedback) can be worse than the disease (higher levels of distortion). As Anthony states, the low order distortion produced by tubes in generally benign subjectively. Adding feedback will lower the absolute values but increases the complexity of the distortion spectrum leading to subjective consequences.Quote:
Originally Posted by anthonyTD
Hi Anthony,
What I was getting at is when you design an amp with already low and acceptable distortion figures do you then go on to bang your head agianst a wall to get it even lower or do you move your attention to other areas that may also have a impact on the sound.
Just wondering if that to some (designers of SS amps) getting lower distortion than your rival become all emcompasing to the point where other important factors are ignored.
Hi Tim,
Agreed that some sand amps sound good,it's just for me none I've heard equal what a good valve amp can do.To my ears,even a mediocre valve amp sounds better than a good sand amp.
hi paul,Quote:
Originally Posted by Primalsea
i see, well as the post above explains [i should coco] once you reach a level that is exceptable,[we are all diffrent] there are other areas that would benefit more from a designers point of view, ie power supplies, circuit layout. to get the lowest posible natural noise floor from a specific circuit [ie without using feedback to artifically lower it] can be equally as important as ultra low distortion figures.
anthony,TD...
So what decent and afordable valve amp with a reasonable power output will give silent operation when no music is playing into a pair of 103db sensitivity speakers?
And furthermore will it be flat in frequency response from below 20hz upwards?
hi steve,Quote:
Originally Posted by sastusbulbas
thats easy, my soul amplifiers, well they have two out of the three above, affordable well, thats down to the individuals acceptance of the term!
anthony,TD...
Steve,
Chat to Anthony with the budget you have in mind (as long as it's viable) and I'm sure he'll come up with a design that will shock and stun you ;)
Marco.
Haha, indeed! :eyebrows:Quote:
hi steve,
thats easy, my soul amplifiers, well they have two out of the three above, affordable well, thats down to the individuals acceptance of the term!
anthony,TD...
Would you not design a scaled-down version of your Copper amps (not using a Copper chasis, though) if someone wanted, say something that would sound like the dog's danglies for around a grand or so.
You know that you have 'de technology', massa ;)
Marco.
Prices and specifications guys? :scratch:
Remember I am poor and have two kids and a wife :(
:lolsign:
Edit,
I do miss certain valve traits, and would like to go down that route, but most valve amps cost way more than SS designs and are noisier and less capable in certain areas such as bass.
i would beg to differ , i once tried out a monoblock pair of SET kt88's and it sounded dreadful, it was like listening to MW or SW radio or as dougie dunlop used to say a bag o' nail's .Quote:
Originally Posted by Ali Tait
These amp's were cottage industry type
Do you have a need for a lot of power? Define reasonable.I'd have thought with 103 dB speakers,a watt or two would be more than enough.Only way I think to do it at a reasonable price would be to diy.
A second hand World Audio Design KEL84 or one of those little Chinese Yarland EL84 amps would be possible options. ORNEC sold the Yarlands for less than £200 but looks like the company is in the middle of a change over at the mo.
My friend bought 3 and lent them to me for a while so I could use them with my active speakers. They were very good and quiet. The KEL84 is very quiet and a very good amp.
Also dare I say a T-Amp will work well with high sensitivity speakers. They became very popular and then it all died away. They are very good though, I put 3 into a single box for a friend so he could tri amp his Epos ES22's.Not valve I know.
The speakers are at the moment used in a room roughly 80ft long by 80ft wide, 150w solid state seems to have problems, though I feel the amp power supply is hindering things, I also have a small 40 watter? which suffers at volume.Quote:
Originally Posted by Ali Tait
At home I have 100 watt Classe power amps, which do well, and have serious toroids which I feel makes a difference in the bass, for example my Technics is silent but 100w per channel, but again bass seems lacking in comparison to the likes of my Krell and Classe. I have contemplated selling the Classe power amps, and trying to get a second hand McIntosh 275 power amp or similar, but have also been thinking of a second Classe for bridging.
My Kef R107 do not get on with valve amps, particularly if I have the LF extension cut of below 20hz, I seem to be able to get usable extension down to 15hz, 10hz being a little subdued, but to sustain any usable output at these extremes I find I need a decent amp, only the bigger Krells and such seem comfortable there, with most others with plain watts without current proving detrimental. And I seem sensitive to any amplifier noise, such as hiss or hum.
I like drums percussion and such, low frequency stuff that stops and starts on a dime, much of it out of phase. I would happily run an active PMC/Bryston BB5 system at home if I had the room and money.
As an example I find my Krell which is giving me around 600w into 4 ohm, with plenty of current, is just about right for teh main system with the Kef, the pre is a KRC 3 which gives lower output than my previous Audio Research valve pre's though, and I can put my volume all the way round for a short period, its quite clean and does not sound as loud as it actually is?
Hi Chris,Quote:
Originally Posted by chris@panteg
Can you be more specific please? We like the naming of names in circumstances like this :)
Cheers!
Marco.
Well if that's the kind of power you need,buying something commercial would be hideously expensive.You could diy or buy this-
http://www.audio-talk.co.uk/phpBB2/v...028&highlight=
Sorry Marco they were i think a diy job by an enthusiast they were not that well made
i don't have a name for them' but my point is that a poor amp be it valve or SS is a poor amp , at the same time i tried a big and beefy EL84 PP amp giving something like a 100 watts again i think it was DIY or cottage industry job but it was fantastic driving a pair of
acoustic energy AE1's in rosewood which i had at the time ,alas the amp was not for sale but it was fun.