Reinventing the wheel

[cloth-ears]

Just a thought but I would be interested in your opinions. I believe that the best amplifier in the world has already been invented, and has been for quite some time. The 70’s was a good time for amplifiers. Many great models were brought to market in those days both from the UK and Japan.

Since then many more have been created. Smaller, possibly better looking and with the added convenience of remote control. With distortion levels as low as three decimal places and a signal to noise ratio of 100db or better what more do we need. Bearing in mind that the best speakers available have distortion values up to 100 times that of the finest amplifiers it begs the question, do we really need any more amplifiers?

I don’t think we do, I believe manufactures are just reinventing the wheel. If you believe that we haven’t quite got there yet then I would be interested in your opinion as to what more needs to be done.

[Marco]

The 70’s was a good time for amplifiers. Many great models were brought to market in those days both from the UK and Japan.


Well, yes, outside of those featured in the famous [read as ridiculous] 'spec wars', which sounded 'grey and boring' - dreadful things. However, the best ones from the 70s certainly weren't mainstream models, and mostly Japan only. You're not another one of those 'distortion fetishists', are you? ;)

IMO, the best era for amplifiers was the 50s, when some amazing ones were born, with glowing bottles in them, many of which haven't been bettered since!

Marco.

[cloth-ears]

Well, yes, outside of those featured in the famous [read as ridiculous] 'spec wars', which sounded 'grey and boring' - dreadful things. However, the best ones from the 70s certainly weren't mainstream models, and mostly Japan only. You're not another one of those 'distortion fetishists', are you? ;)

The best era for amplifiers was the 50s, when some amazing ones were born, with glowing bottles in them, many of which haven't been bettered since!

Marco.

I did say many and not "every"

[Marco]

Sure, so which were your favourites? :)

Marco.

[Andrei]

Just a thought but I would be interested in your opinions. I believe that the best amplifier in the world has already been invented, [...] what more needs to be done.
Getting Class D to sound like Class A would be good.

[cloth-ears]

Sure, so which were your favourites? :)

Marco.

I had a Leak 22 which was nice. At the time I had some Tannoy speakers that were huge, couldn’t keep them for long. The Leak didn’t have enough oomph to drive smaller less efficient speakers so I got a Quad 33, it did the job. Now I have a 909 that I believe takes some beating. I really am that old

[cloth-ears]

Getting Class D to sound like Class A would be good.

That would be difficult. The whole ethos of Class A is that it’s non-switching. Class D on the other hand is always switching, that is what makes it Class D

[PaulStewart]

Japan produced some amazing amps in the 70s from my own experience models like JVC'S 3030 series and the top of the range AX Super-A amps were amazing and I think not really bettered by many newer solid state designs. However, semi conductor design has progressed and I think that SOME modern amps have better ?faster? current delivery. To be honest, I've yet to hear any SS amp that can hold a candle to a good hot bottle :) My current amp uses 300Bs, developed in 1938..... In fact my guilty secret is that all the time I was working with JVC although I had both and AX9 and a P3030/M3030 set up at home, most often unless a member of the audio press was coming round, I had my Alex Shackman modded (KT77) Quad IIs hooked up. :lol: Class D or more likely it's successor has a lot to offer, but is, in my opinion, way off what the best discrete component SS amps can offer, but this approach which is more energy efficient and cheaper to produce, is sadly in my opinion, probably the path that many manufacturers will follow.

[struth]

Getting Class D to sound like Class A would be good.

Quite like a good "D" class amp. had one of the best "A" class as well in the A1000 which was 50w of loveliness(they wont make that again)

[Beobloke]

Well, yes, outside of those featured in the famous [read as ridiculous] 'spec wars', which sounded 'grey and boring' - dreadful things..

Such as?

[Marco]

Pretty much anything mainstream Japanese, from the 'usual suspects'. Can't remember any exact models, as I was rather young. However, the more feedback applied to the circuit, in order to lower the THD figures by another .00000000000%, or whatever, the worse [more musically strangled] they sounded! ;)

The ridiculous 'spec wars' back then ably demonstrated how futile it was judging how good an amp was, or otherwise, just by its technical specifications.

In fact, if you read most reviews in mags, from back then, 'techy stuff' (graphs and shit) was generally all you got, which bored me to tears... You got very little of what the reviewer actually thought stuff sounded like (the important bit)! :rolleyes:

Marco.

[Macca]

Or you could argue that people like a bit of distortion and a lot of the kitchen table UK amps had it whereas their lab-designed Japanese rivals didn't. The Jap amps were honest but the UK amps made the music sound 'live'. Not everyone preferred that sound, I was never that keen, for one.

[wee tee cee]

The D class amps from the likes of Temple audio or Amptastic can sound fantastic. Not just limited to easy to drive speaker, they do a great job with statics.

Well worth a try when implemented well and fed clean power.

[Marco]

Or you could argue that people like a bit of distortion and a lot of the kitchen table UK amps had it whereas their lab-designed Japanese rivals didn't. The Jap amps were honest but the UK amps made the music sound 'live'. Not everyone preferred that sound, I was never that keen, for one.

Yes you could argue that, but it wouldn't be my opinion. For me it's not a case that one deliberately likes distortion, but rather that some of that distortion is part of the music signal, and by 'trimming it off', in a quest for the amp to measure better, makes the resulting sound bland and musically boring. I've heard the effect many times.

For me, the SS amps in those days which were designed like that (via a 'measurements first' approach) possessed that grey/flat/lifeless sound, which I don't consider as in any way musically accurate, represented solid-state at its worst. Thankfully, good SS amps these days sound nothing like that!

Marco.

[Arkless Electronics]

The best amps certainly were not made in the '70s. Many things have been learned in amp design since then and we have much better solid state devices than we had then (although, conversely, there are certain parts that have become obsolete and not replaced. Mainly due to the SMD and digital "revolution", components that become no longer profitable to multinational corporations tend to be obsoleted).
Even valve amps are vastly better than "back in the day", due both to component improvements and to new ways of using valves alongside solid state devices e.g. if you wanted a really "stiff" HT supply back in the day you couldn't get 1000uF 450V electrolytics.... nor would it be practicable to use DC regulated heater supplies back then and that's just two examples that spring to mind.

[Marco]

The best amps certainly were not made in the '70s. Many things have been learned in amp design since then and we have much better solid state devices than we had then (although, conversely, there are certain parts that have become obsolete and not replaced. Mainly due to the SMD and digital "revolution", components that become no longer profitable to multinational corporations tend to be obsoleted).
Even valve amps are vastly better than "back in the day", due both to component improvements and to new ways of using valves alongside solid state devices e.g. if you wanted a really "stiff" HT supply back in the day you couldn't get 1000uF 450V electrolytics.... nor would it be practicable to use DC regulated heater supplies back then and that's just two examples that spring to mind.

I agree with most of that, Jez. However, I think that some of the best valve amps from the 50s (and even 40s) can still sound superb, by today's standards.

Did you leave NEBO before the Radford went into Steve/Rich's system? If so, you missed how utterly stunning it sounded [a 50 year old design] - and almost as good as the brand new 300B amp Nick built, at considerable cost, containing all the best modern components! :)

I agree that component quality (stuff like capacitors and resistors) has improved massively since those days, but some of the hand-wound transformers and point-to-point wired circuits back then were truly superb, and indeed the latter, in some cases, still act as the benchmark today.

Marco.

[Arkless Electronics]

Yep I'd gone by then. Think how much better still the Radford could have been if designed today. I'm sure Arthur would have loved to have had access to modern components!

[Marco]

Oh yes, I know and fully accept that. However, the basic (infrastructure) of the design was bloody good to start with! ;)

Shame you missed hearing the Radford, as it was pretty special.

Marco.

[Macca]

If you could build an ss amp with decent power that sounds like that Radford you'd have it cracked.

[Arkless Electronics]

If you could build an ss amp with decent power that sounds like that Radford you'd have it cracked.

With remote control and at £299? I'll be on to it on the 32nd of the month :D

[walpurgis]

If you could build an ss amp with decent power that sounds like that Radford you'd have it cracked.

I've got one thanks! :D

[Marco]

If you could build an ss amp with decent power that sounds like that Radford you'd have it cracked.

Indeed - and you can bet that the Radford was listened to, as well as just measured, unlike some of the Jap SS amps of the 70s... ;)

The process is called 'voicing', and any audio designer who doesn't also use his ears, as well as his test equipment, when designing something, doesn't deserve to be called an audio designer!

:exactly:

Marco.

[Arkless Electronics]

Indeed - and you can bet that the Radford was listened to, as well as just measured, unlike some of the Jap SS amps of the 70s... ;)

The process is called 'voicing', and any audio designer who doesn't also use his ears, as well as his test equipment, when designing something, doesn't deserve to be called an audio engineer!

:exactly:

Marco.

The Radford power amps went through very rigorous bench testing and delivered a technical performance that is still excellent by today's standards, especially THD. Arthur Radford's trick was to use MORE negative feedback than other valve amps. This required unusually good output transformers in order to maintain bandwidth and minimise phase shift enough to allow all that feedback to work without the amp oscillating. He also hired Arthur Bailey to design a pentode phase splitter to give even more bandwidth and so allow more feedback. Negative feedback isn't always bad ;) It must be used erm.. judiciously though.
I use both instruments and ears in designing my stuff. It's the only method that works properly IMHO. I'm not a follower of Doug Self's measure only approach at all.... :)

[Marco]

I know you do, Jez - and that's why you get such good results! The BEST equipment *always* sounds good (read as 'musically accurate'), as well as measures properly :)

Doug Self? Vaguely heard of him, but on those grounds, not someone I would respect or who's designs I'd be interested in hearing.

Marco.

[cloth-ears]

I dislike it when an amplifier is defined as sounding musical, that’s not its job. Its only purpose is to make small things big. In doing this it should as best as possible neither remove nor add anything. If a tune going in is musical it should sound as such when it comes out the other side.

The problem is in the mix. Whoever does the final mix has a target audience in mind. A pop song that had to sound good on an AM radio or jukebox would be mixed in such a way that when played on any decent equipment would probably sound rubbish. They still do it today, anything x-factor or pop idol is mixed for the great unwashed to be played on ear speakers. When played on a decent setup the bass is bloated and the treble is a little on the light side. I believe that this is one of the reasons that the big Jap amps got such a bad press. The vast majority of the music of that era was mixed to sound good on lesser amps. Thus when the sound was played on a “small in, big out” neutral amp it was often described as being thin. These amps now sound as they should when matched with well produced digital music. I share this opinion with many others but I’m almost certain that many on here will disagree with me. Such is life

[walpurgis]

Some amplifiers sound less good than others. This can be a because of a system mismatch or just a not so good amplifier. Therefore, I'd suggest an amplifier that is described as "musical', is one that presents satisfactory results in the context of its use.

[Marco]

I dislike it when an amplifier is defined as sounding musical, that’s not its job.

Essentially I agree with where you're coming from, Bob. However, what I mean is 'musically accurate', i.e. that which replicates, as closely as possible, the sound of real voices and instruments (as far, of course, as the transparency of the partnering recording allows).

In my experience, some amplifiers I've heard, particularly those born solely from measurements, are incapable of the above (that is, revealing the true nature of the recordings they're presented with). They are, in effect, musically inept.

That is because they've had the 'life' strangled out of them from the beginning (often in the pursuit of attaining the lowest distortion figures, über-alles), and due to the manufacturer/designer in question not listening to the result, and making final adjustments to the circuit by ear, before putting the finished product into production, thinking that 'my test apparatus knows all'.

The 'tuning by ear' part is essentially what makes the amplifier sound 'musical', i.e. allows it to faithfully reproduce the recordings it's presented with (rather than 'edit' them accordingly, via inherent shortcomings in its circuitry, resulting from injudicious component selection, and/or just bad decision making), as measurements only tell part of the story: the basic stuff. It's the 'ears bit' at the end that makes or breaks things, musically.

It's like baking a cake: you need both the right recipe to follow, and to successfully combine the right ingredients, or the finished product will be substandard.

That's why the finest sounding amplifiers are generally produced by designers, who have the most accomplished 'grasp' of how real voices and instruments should sound, together with the technical wherewithal to judiciously implement their ideas into an electrical circuit, which in turn will deliver the highest standards of fidelity, and most importantly, musicality, (since, after all, the goal is to reproduce recorded MUSIC, not just sound waves). The former is much more complex.

You need BOTH a fundamental understanding of how real voices and instruments should sound, what one could call 'educated ears', as well as technical prowess, in order to build the best gear. To achieve that, it's about symbiotically marrying ART with SCIENCE. Employing the use of one, is no good without the other! :)

Marco.

[Audio Advent]

That would be difficult. The whole ethos of Class A is that it’s non-switching. Class D on the other hand is always switching, that is what makes it Class D

That has nothing to do with the sound (since Andrei's quote was about making Class D SOUND like Class A).

[Audio Advent]

Just a thought but I would be interested in your opinions. I believe that the best amplifier in the world has already been invented, and has been for quite some time. The 70’s was a good time for amplifiers. Many great models were brought to market in those days both from the UK and Japan.

Since then many more have been created. Smaller, possibly better looking and with the added convenience of remote control. With distortion levels as low as three decimal places and a signal to noise ratio of 100db or better what more do we need. Bearing in mind that the best speakers available have distortion values up to 100 times that of the finest amplifiers it begs the question, do we really need any more amplifiers?

I don’t think we do, I believe manufactures are just reinventing the wheel. If you believe that we haven’t quite got there yet then I would be interested in your opinion as to what more needs to be done.

If you don't know much about designing and building amplifiers this might be your conclusion just because you still like some old amps...

I don't know much about designing or building amplifiers myself but if you listen to people who really really do, people like Nelson Pass, they will let you know that new technologies allow them to design amplifiers in new ways, different topolgies. The differences may well appear to be subtle to the non-designer but to the designers they are quite major steps. Nelson Pass is often writing about new discoveries of newly-invented or developed semi-conductor designs which excite him for various design reasons and sonic potential.

And Class D of the quality we have today wasn't previously possible.

[Marco]

Nelson Pass - now *that* is someone I really admire and respect. Wonderful designer, and supremely talented.

Marco.

[Gazjam]

The idea of using current technology to improve on the old, as in better quality Class D, or in my case applying modern techniques to valve amp design can move amp design forward imo.

Had a 300B Set power amp designed and built for me by Nick Gorham, inside it looks like no other SET amp I've seen.
NOT your traditional valve amp with established design ideas.
Doesn't sound like one either, particularly in the bass.

Because whats worked in the past has been good, it might not necessarily mean there's no way to improve amp design?

[Marco]

Indeed - and I fully concur.

However, if you ask Nick, I'm sure he'll tell you that your amp was based around one of the classic valve circuits (usually from the 1950s), which he will have modified and implemented in his own (very effective) way.

The reality is, there are only so many good amplifier circuits to choose from in the first place! ;)

Marco.

[Arkless Electronics]

Indeed - and I fully concur.

However, if you ask Nick, I'm sure he'll tell you that your amp was based around one of the classic valve circuits (usually from the 1950s), which he will have modified and implemented in his own (very effective) way.

The reality is, there are only so many good amplifier circuits to choose from in the first place! ;)

Marco.

There's only eight notes in the musical scale but they can be put together in rather a few combinations ;)

[lurcher]

There's only eight notes in the musical scale but they can be put together in rather a few combinations ;)

12 in the western equal tempered scale, much more when you add 1/4 and 1/2 notes.


However, if you ask Nick, I'm sure he'll tell you that your amp was based around one of the classic valve circuits (usually from the 1950s), which he will have modified and implemented in his own (very effective) way.

Well, not so much, single ended output stages had just about been relegated to Danset portables by the 1950's. If you ignore the power supply and active loads however, the circuit would be understood by the 1920's, though capacitive coupling was less common due to transformers being more common.

[Arkless Electronics]

Eight in an octave, twelve in a chromatic scale... pedant! :D And there are semi tones in a chromatic scale...

Single ended was the most common output stage by far during the valve era. Not just Dansette's. Almost every table radio, TV, tape recorder etc used single ended 'cos it was cheaper at these (3 - 5W) output levels. Usually a pentode or beam tetrode. In Europe EL84 and UL84 by far the most common. Only "deluxe" models used push pull.

[Clive197]

What about the Devialet range of amps. Class A for the 1st 10 watts then brings in class D. Personally after a dem, I've decided that the amp is not for me. Furthermore having a phono stage built in and using a ADC to convert to digital then amplifying is very interesting but stupid! Totally defeats the point of vinyl.

[Macca]

What about the Devialet range of amps. Class A for the 1st 10 watts then brings in class D. Personally after a dem, I've decided that the amp is not for me. Furthermore having a phono stage built in and using a ADC to convert to digital then amplifying is very interesting but stupid! Totally defeats the point of vinyl.

Well not really - running it through an A 2 D then a D 2 A doesn't mean you'll lose those lovely 2nd harmonics ;) . It is very unlikely that you will even notice a difference. But if you don't like the amplification anyway the point is moot.

[Audio Advent]

12 in the western equal tempered scale, much more when you add 1/4 and 1/2 notes.


So imagine the amazing music that can be made with an orchestra of swanee whistles!

[Audio Advent]

Furthermore having a phono stage built in and using a ADC to convert to digital then amplifying is very interesting but stupid! Totally defeats the point of vinyl.

Only in idiology - not necessarily sonically. Listen more, think less ... but you listened and didn't like the sound of the amp itself, so you're half way there :)

[lurcher]

Eight in an octave, twelve in a chromatic scale... pedant! :D And there are semi tones in a chromatic scale...

Single ended was the most common output stage by far during the valve era. Not just Dansette's. Almost every table radio, TV, tape recorder etc used single ended 'cos it was cheaper at these (3 - 5W) output levels. Usually a pentode or beam tetrode. In Europe EL84 and UL84 by far the most common. Only "deluxe" models used push pull.

I can be far more pedantic that that. An Octave is a interval not a scale. There are eight notes in a major and natural minor scale, 5 in a petatonic, 6 in a augmented and so on. But to be more pedantic scales are built out of intervals not notes. All the notes in a chromatic scale are a semitone apart, but the notes are not semi tones as such. Again semitone is a interval not a note.

Saying there were 8 notes in a Octave would sound ok, all the notes in C maj are C D E F G A B, so they are all notes, but the notes in Eb maj are E♭ F G A♭ B♭ C D, so if they are all notes as well (which they are) so thats three more notes to add to the set of notes, so that gives us 10, and so on till we get all 12 notes in the chromatic scale. But what the note (for example) between the notes D and E is called depends on the context, either E♭ or D#. But of course if its not an equal tempered scale, then E♭ or D# are potentially different frequencies.

[Arkless Electronics]

I can be far more pedantic that that. An Octave is a interval not a scale. There are eight notes in a major and natural minor scale, 5 in a petatonic, 6 in a augmented and so on. But to be more pedantic scales are built out of intervals not notes. All the notes in a chromatic scale are a semitone apart, but the notes are not semi tones as such. Again semitone is a interval not a note.

Saying there were 8 notes in a Octave would sound ok, all the notes in C maj are C D E F G A B, so they are all notes, but the notes in Eb maj are E♭ F G A♭ B♭ C D, so if they are all notes as well (which they are) so thats three more notes to add to the set of notes, so that gives us 10, and so on till we get all 12 notes in the chromatic scale. But what the note (for example) between the notes D and E is called depends on the context, either E♭ or D#. But of course if its not an equal tempered scale, then E♭ or D# are potentially different frequencies.

Obviously :)

[anthonyTD]

Absolutely agree! :)
All of the best designs from the past could be bettered in some way, using the best component technology we have today.
As for valve amps, my main goal with the hybrid amps i did was to combine the best of old and modern technolgy, and come up with something that was very diffrent in terms of performance etc.
The best amps certainly were not made in the '70s. Many things have been learned in amp design since then and we have much better solid state devices than we had then (although, conversely, there are certain parts that have become obsolete and not replaced. Mainly due to the SMD and digital "revolution", components that become no longer profitable to multinational corporations tend to be obsoleted).
Even valve amps are vastly better than "back in the day", due both to component improvements and to new ways of using valves alongside solid state devices e.g. if you wanted a really "stiff" HT supply back in the day you couldn't get 1000uF 450V electrolytics.... nor would it be practicable to use DC regulated heater supplies back then and that's just two examples that spring to mind.

[Marco]

Well not really - running it through an A 2 D then a D 2 A doesn't mean you'll lose those lovely 2nd harmonics... It is very unlikely that you will even notice a difference. But if you don't like the amplification anyway the point is moot.

But you're complicating the signal path completely unnecessarily, and that will be sonically detrimental, *that* is the point! ;)

The accurate reproduction of vinyl is subject even more to the rules of K.I.S.S, than anything in the digital domain, due to the 'delicacy' of the music signal. It's so easy to fuck it up, and once done, cannot be 'repaired' later in the chain.

When I rip vinyl to CD (or create a 'needle drop'), it never sounds the same (as good) as it does when the record is played 'as is', with no conversion involved. The digitisation process always induces an easily discernible signature on the recreated sound - and not a desirable one either.

Marco.

[Marco]

Well, not so much, single ended output stages had just about been relegated to Danset portables by the 1950's. If you ignore the power supply and active loads however, the circuit would be understood by the 1920's, though capacitive coupling was less common due to transformers being more common.

Point taken, but you know where I'm coming from. Completely new circuits from scratch, with valve amps, are a rarity, if even they exist :)

Marco.

[Arkless Electronics]

But you're complicating the signal path completely unnecessarily, and that will be sonically detrimental, *that* is the point! ;)

The accurate reproduction of vinyl is subject even more to the rules of K.I.S.S, than anything in the digital domain, due to the 'delicacy' of the music signal. It's so easy to fuck it up, and once done, it cannot be 'repaired' later in the chain.

Marco.

Indeed. And as it's possible to get the RIAA accurate to very tight limits (0.1dB etc) using analogue circuitry... and in the digital case it would be necessary to use an unequalised analogue amplifier (I've not looked at such circuitry but would expect that to be the case) to get it to a high enough level for the ADC... what is the point?

[Arkless Electronics]

Point taken, but you know where I'm coming from. Completely new circuits from scratch, with valve amps, are a rarity, if even they exist :)

Marco.

COMPLETELY new circuits are indeed rare but we are still "discovering" circuitry in valve test gear, military stuff etc which is then adapted for audio use... ok most of it's now been done even in that area but a few surprises come along! Then there is the combining of valves with mosfets, jfets or bipolar transistors to make hybrid versions of circuits which once would have been all valve... or indeed all solid state! There's still plenty of electronic notes to make new tunes from ;)

[lurcher]

Indeed. And as it's possible to get the RIAA accurate to very tight limits (0.1dB etc) using analogue circuitry... and in the digital case it would be necessary to use an unequalised analogue amplifier (I've not looked at such circuitry but would expect that to be the case) to get it to a high enough level for the ADC... what is the point?

Yes, I looked at this a bit ago, and when you add the 40dB range of the original RIAA encoding (20Hz-20kHz), to the overload margin you would need to build in to cope with scratches, you find that even a perfect 24bit converter doesnt give you anything like the dynamic range you expected to have at the start. An ADC after the input stage and RIAA eq would work ok, but once you have done those bits a phono stage is simple, so (as you say) whats the point?

[lurcher]

Point taken, but you know where I'm coming from. Completely new circuits from scratch, with valve amps, are a rarity, if even they exist :)

Marco.

Generally, Completely new circuits from scratch are a rarity no matter what the technology. A new device may hit the market that allows us to do something old in a way that looks new, but generally isn’t. As I said before, the cutting edge of analogue design has long since left the area of audio. Marketing departments may claim otherwise and those with short memories or lack of old text books may mistake the old for the new.

[Marco]

Generally, Completely new circuits from scratch are a rarity no matter what the technology. A new device may hit the market that allows us to do something old in a way that looks new, but generally isn’t. As I said before, the cutting edge of analogue design has long since left the area of audio. Marketing departments may claim otherwise and those with short memories or lack of old text books may mistake the old for the new.

Ha - we're in complete agreement there! ;)

Marco.

[Marco]

COMPLETELY new circuits are indeed rare but we are still "discovering" circuitry in valve test gear, military stuff etc which is then adapted for audio use... ok most of it's now been done even in that area but a few surprises come along! Then there is the combining of valves with mosfets, jfets or bipolar transistors to make hybrid versions of circuits which once would have been all valve... or indeed all solid state! There's still plenty of electronic notes to make new tunes from ;)

Yup, plenty of 'jolly japes' to come yet! You bring up a good point with hybrids. Done well, they can be superb :)

Marco.

[Macca]

Yes, I looked at this a bit ago, and when you add the 40dB range of the original RIAA encoding (20Hz-20kHz), to the overload margin you would need to build in to cope with scratches, you find that even a perfect 24bit converter doesnt give you anything like the dynamic range you expected to have at the start. An ADC after the input stage and RIAA eq would work ok, but once you have done those bits a phono stage is simple, so (as you say) whats the point?

I think if you are using a Devialet you don't have the option as it is digital all the way. But if we accept that an AD DA loop is not transparent what does that do to sound quality of records cut using a digital lathe? That is where the logic of that argument fails.

[Arkless Electronics]

Generally, Completely new circuits from scratch are a rarity no matter what the technology. A new device may hit the market that allows us to do something old in a way that looks new, but generally isn’t. As I said before, the cutting edge of analogue design has long since left the area of audio. Marketing departments may claim otherwise and those with short memories or lack of old text books may mistake the old for the new.

We are pretty much saying the same thing but from a different angle here... If "A new device may hit the market that allows us to do something old in a way" well that's still new, in as much as it hasn't been done in quite that way before and it may allow the old job to be done much better. If one studies late 60's Tektronix service manuals one will find all sorts of hybrid (valve/solid state) circuitry that could be called "new" or "cutting edge" at the time, and still so today if applied to a field it was never intended for, such as audio. Then add solid state devices that were not around in the late 60's and we have room for further improvement. It's more a case of continual refinement than totally new ideas of course. If a new amplifier is created using Silicon Carbide mosfets alongside valves for example then the circuitry used is not new in topology but it's still new to the hi fi market, never been done before etc.

[lurcher]

I think if you are using a Devialet you don't have the option as it is digital all the way. But if we accept that an AD DA loop is not transparent what does that do to sound quality of records cut using a digital lathe? That is where the logic of that argument fails.

Well, no, it doesn’t affect the argument at all. I was not saying I had any view on the transparency or not of the AD/DA process, but on the available dynamic range being far less than expected. A lathe does not have to deal with surface noise and scratches so thats immediately a extra 20dB it has to play with, and I dont know if the RIAA curve is applied in the digital realm or not, so that potentially gives another 40dB.

You seem to have decided I am making a different point to the one I am making, have claimed to have found a flaw in the logic of the point I was not making, and then declared that defeating a point I didnt make has some bearing on the point I did make.

Not that I was making a argument, I just summarised the result of my looking at the available and needed dynamic range in a hybrid phono stage.

[lurcher]

We are pretty much saying the same thing but from a different angle here... If "A new device may hit the market that allows us to do something old in a way" well that's still new, in as much as it hasn't been done in quite that way before and it may allow the old job to be done much better. If one studies late 60's Tektronix service manuals one will find all sorts of hybrid (valve/solid state) circuitry that could be called "new" or "cutting edge" at the time, and still so today if applied to a field it was never intended for, such as audio. Then add solid state devices that were not around in the late 60's and we have room for further improvement. It's more a case of continual refinement than totally new ideas of course. If a new amplifier is created using Silicon Carbide mosfets alongside valves for example then the circuitry used is not new in topology but it's still new to the hi fi market, never been done before etc.

Yes I know, I was concurring with your point and replying to Marco, not you. Don’t assume every post I make is in response and/or disagreeing with yours :-). That way lies paranoia or megalomania.

[Marco]

I think if you are using a Devialet you don't have the option as it is digital all the way. But if we accept that an AD DA loop is not transparent what does that do to sound quality of records cut using a digital lathe? That is where the logic of that argument fails.

As usual, I can only report what my ears and experience tell me, and in my experience, digitising any part of the vinyl reproduction chain has a negative impact on musical integrity.

Digital lathe? Perhaps that's why the finest 1950s/60s [jazz and classical] recordings on vinyl are often considered by enthusiasts as sonically unequalled? ;)

Marco.

[Audio Advent]

Digital lathe? Perhaps that's why the finest 1950s/60s (jazz and classical] recordings on vinyl are often considered by enthusiasts as sonically unequalled? ;)

Marco.

Yet 80s funk and synth-pop sounds better than 50s/60s jazz/classical .... so you're stuck with 50s/60s music. I tend not to listen to enthusiasts who enthuse about things I have no enthusiasm for!

[Marco]

Quite right too, as music preference is a personal thing :)

I was talking purely about recording quality: the benchmark for ultimate high-fidelity, as considered by the cognoscenti, not musical merit, although I also enjoy jazz and classical music almost as much as I do 80s funk and synth-pop!

However, if you enjoy listening to REAL instruments, supremely played and well-recorded (count me in), then few things can touch some of the 1950s vinyl jazz recordings, on the likes of Blue Note. Played on a top-notch T/T and system, it's like having the sound of a saxophone hard-wired to your ears!

Marco.

[cloth-ears]

If you don't know much about designing and building amplifiers this might be your conclusion just because you still like some old amps...

I don't know much about designing or building amplifiers myself but if you listen to people who really really do, people like Nelson Pass, they will let you know that new technologies allow them to design amplifiers in new ways, different topolgies. The differences may well appear to be subtle to the non-designer but to the designers they are quite major steps. Nelson Pass is often writing about new discoveries of newly-invented or developed semi-conductor designs which excite him for various design reasons and sonic potential.

And Class D of the quality we have today wasn't previously possible.

I suppose I if you don’t know much about amplifier design that may well be the case. Although amplifier design is not my field of expertise I am pleased to report that I do have some knowledge in this area. Firstly I didn’t say the best amplifier in the world was built in the 70’s, I merely said that the 70’s was a good age for amplifiers, which it was. With regard to Class D amplifiers, they were never designed to answer any shortfalls in the fidelity of bipolar amps. Class D came into being for reasons of economy, weight and size. They operate in a way not too dissimilar to switch mode power supplies. They were never intended to be used as audiophile amplifiers. Mobile phones, portable audio and the like was their raison d'être. They work pretty well at low frequencies so have found their way into domestic subwoofers and PA equipment. There is no real mileage in trying to get Class D to sound like Class A (if indeed it’s possible). Class A is the polar opposite of Class D. Non switching amplifiers have a different “sound” to constantly switching amplifiers for a number of reasons, not least of which is that Class D amplifiers require inductors and capacitors at the output stage to act as a low pass filter. I believe that Class D amps have come a long way and I’m sure that they will continue to improve but IMHO they still have a long way to go in order the match the performance of a half decent bipolar amp.

[Light Dependant Resistor]

Quite right too, as music preference is a personal thing :)

I was talking purely about recording quality: the benchmark for ultimate high-fidelity, as considered by the cognoscenti, not musical merit, although I also enjoy jazz and classical music almost as much as I do 80s funk and synth-pop!

However, if you enjoy listening to REAL instruments, supremely played and well-recorded (count me in), then few things can touch some of the 1950s vinyl jazz recordings, on the likes of Blue Note. Played on a top-notch T/T and system, it's like having the sound of a saxophone hard-wired to your ears!

Marco.

A forum like AOS should steer its members toward what is possible with audio.This thread started with the best amplifier
was made in the 1970's but did not name it ?

The sad facts are that we fail collectively to leave a imprint on what manufacturers should be doing.
Pacific Microsonics and its main influence Prof Keith Johnson, and Bob Adams ex DBX now Analog Devices
both proved it is possible to bring better ways of doing audio to the marketplace. In the case of Pacific
Microsonics the PMD100 integrated circuit and others , and in the case of Bob Adams a steadfast belief
in Delta Sigma Modulation first seen in the DBX 700, but now thankfully available in a range of Analog Devices
DAC's ,

Here is a start on where I think the audio industry should head:

CD players be offered with either Dolby or DBX to enhance dynamic range
CD players be offered with selectable dither like, HPTPDF TPDF, SNR2 and variable shaping
and Transient capture mode ( DBX ) and provide Delta Sigma Modulation DAC's
CD players be provided with BNC type connectors and digital links
CD players be provided with high quality op amps like LM4562 and LME49710

Amplifiers be provided at a minimum with current and voltage regulation of front end components
and where possible capacitive multiplier circuits, instead of plain capacitance

For digital storage abandon MP3 and proprietary type files, and replace with Ogg or Flac.

Cheers / Chris

[cloth-ears]

A forum like AOS should steer its members toward what is possible with audio.This thread started with the best amplifier
was made in the 1970's but did not name it ?

Once again, I did not say that the beast amp was made in the 70's. Please read the original post

[PaulStewart]

Here is a start on where I think the audio industry should head:

CD players be offered with either Dolby or DBX to enhance dynamic range

:mental::mental::mental::mental::mental:

[Light Dependant Resistor]

Hi Paul
As you would know to do either DBX or Dolby with a CD player
involves a discrete compression circuit and discrete expansion circuit
or more simply a record circuit and a playback circuit. Real time
processing being possible, if two discrete circuits are available.

You and me are likely the only ones on the forum with either Dolby or
DBX. Give it a try, or if you have already, then I respect your opinion.

But if commenting just from the armchair...that is a bit sad.

Cheers / Chris

[walpurgis]

Dunno about CD, but the effects of Dolby on cassette tape were pretty undesirable in my opinion. I preferred a bit of hiss to the flatness of the sound and perceived loss at the top. I know it was supposed to measure flat after the roll of the Dolby curve was reversed, but it never sounded that way!

[Light Dependant Resistor]

Dunno about CD, but the effects of Dolby on cassette tape were pretty undesirable in my opinion. I preferred a bit of hiss to the flatness of the sound and perceived loss at the top. I know it was supposed to measure flat after the roll of the Dolby curve was reversed, but it never sounded that way!

Same as using a pin for a cartridge stylus, Dolby B was a compromise.
in addressing the shortcomings of cassette. Well set up though a cassette
can give reasonable recording ability and Yes usually with Dolby off.

The point being and good evidence here, that manufacturers are let off with
providing us with just works, rather than providing what is actually possible.

Dither is good example, ask yourself why it is not available on CD players ?
The recording industry would nearly pack their bags and leave if it was not available

Cheers / Chris

[lurcher]

Dither is good example, ask yourself why it is not available on CD players ?

Because its part of the recording process, not the playback?

[Light Dependant Resistor]

Because its part of the recording process, not the playback?

A look at the following product may convince you dither can be and is also used in playback
Page 14. The PMD100 providing 8 selectable dither types. http://www.vt52.com/ftp/semi/pmd100.pdf

Cheers / Chris

[PaulStewart]

Chris, as I have said before, I have used Dolby, DBx and digital recording at a professional level countless times. In my opinion the only product that was better than not using it at all, was Dolby SR and then only in some cases. Even then a well set up tape, using something like AGFA PEM468, set at 0=+7dB and bias set accordingly was better. DBx was and is pants, it sucks..... and blows :) Just rubbish, though some of their recording technology is OK. It seems most things you write on here are at a tangent to reality, and disagree with what the majority of the industy think. I don't think the rest of us are out of step, I think it's you, best of luck

[Light Dependant Resistor]

Hi Paul
No I am not out of step, rather I am stepping rather well.
DBX always set themselves more of a challenge than Dolby
as they dealt with full frequency rather than segments
of frequency as Dolby did.

DBX Yes made mistakes by making Type 2
equipment available, as their direct competition was Dolby B
and the cassette was then popular

But move ahead to about 1985 when the 150x, 155 and 180a became available
and what is known as Type 1 DBX became available and it was very good indeed, having none
of the problems of earlier models. Vangelis in particular using the 180a

I have introduced this concept of using Type 1 to 4 friends
and each enjoy every day and night, the benefit companding brings.

Move ahead further and the 1990's saw DBX concentrating on
musicians and recording studios, Now with so many
beneficial circuits like Type 4, TCM ,TSE Adjustable dither,
each of these has a place in audio. I have written to DBX
to suggest they introduce a audiophile compander capable
of providing these features and they are looking at it.

I also have a Type A Dolby and enjoy it as well.

I think we will have to agree to disagree, but companding and
dither have important roles to play if audio excellence is
what you strive for.

Cheers / Chris

[lurcher]

A look at the following product may convince you dither can be and is also used in playback
Page 14. The PMD100 providing 8 selectable dither types. http://www.vt52.com/ftp/semi/pmd100.pdf

Cheers / Chris

Not so much, HDCS used the low order bits on the CD as control signals to allow dynamic expansion to greator bit depth, the dither selection here relates to the expansion process.

But TBH, whatever.