Johan- I went back and read Self's book last night concerning his definition of "blameless", since he did coin the term. As far as I can tell, it refers only to the reduction of his eight distortion mechanisms, and is purely electrical in nature. It says nothing about how the amplifier sounds, the point being that if those mechanisms are reduced to minuscule levels, there will be no sonic signature from the amplifier. Thus my belief that a "perfect" amplifier may or may not cause listener fatigue, depending on the program source. After all, if the program source were intended to produce listener fatigue, as so many of today's mixes do (see recent thread on bad CDs!), the amp should dutifully produce it. I guess we should agree on a program source that has no fatigue?
Regards,
CH
Regards,
CH
Hi Conrad,
I agree with what you are saying and do hold a certain belief in this approach. WHile self does great work in diminishing these common distortion problems I think this is a large part but only part of the picture. His concepts seem to be a great place to start and he gives some very solid foundations in which to build upon. I dont own his books but wonder if he goes farther into global and local feedback. Many into Selfs work like myself end up inevitably having more in common with the objectives of others who subjectively tune an amplifier as relying on strict electrical measurements can be sort of like eating processed cheese slices vs aged chedder
..
PS:Johan, no worries i enjoy reading the posts even if not 100% related..
Colin
I agree with what you are saying and do hold a certain belief in this approach. WHile self does great work in diminishing these common distortion problems I think this is a large part but only part of the picture. His concepts seem to be a great place to start and he gives some very solid foundations in which to build upon. I dont own his books but wonder if he goes farther into global and local feedback. Many into Selfs work like myself end up inevitably having more in common with the objectives of others who subjectively tune an amplifier as relying on strict electrical measurements can be sort of like eating processed cheese slices vs aged chedder
..PS:Johan, no worries i enjoy reading the posts even if not 100% related..
Colin
Listener fatigue
Thanks Colin.
.... and agreeing with you and Conrad, further adding:
The following does not necessarily refer to you guys, or anybody else that it does not refer to (now that is a profound statement! ). So preaching to the choir, but for completeness sake, some basic hearing philosophy:
I have a problem with a certain view that in an almost derogatory way suggests that specs are allright, but there are still (as in must be) audible things that one cannot measure - ear so sensitive etc. This stance flatly ignores the multitude of tests done over decades at highly regarded centres (not by journalists) to try find out what is audible and what not. To the degree that this has resulted in reproduceable consistent results after using many thousands of subjects, I am really doubting that somewhere in some etherical spheres, something still lurks that we will discover or stand in awe of (re hearing, of course). Ergo, we have a useful "model" of the ear, even though we may not exactly be able to understand it from A - Z.
This is not elevating science arbitrarily; it is about as simple as finding, after enough tests, that a normal person is considered too intoxicated to drive a motor vehicle with a blood-alcohol content above 0,05%, to use an example. It is not that medicos and psychologists claim to be superior (or engineers), it is simply using test results the way science has used it in a million other cases. Science do not know everything, but it knows certain things. In that way I believe one can define that an amplifier will be blameless or otherwise. As said by you, program sources are something else now ..
It does become complex when one includes what was also found during the above tests, and that is the inconsistency in hearing interpretation. This is again not derogatory. Palaeontologists say that our hearing facility evolved as a warning facility. Appreciation of melodius sounds and that sort of music only "arrived" a few seconds before 12:00, on a scale of creation starting at midnight and noon being now. Ears did not evolve as distortion detectors; what exists is the way hearing happens to be and that is not necessary consistent with our terms, in this minute increment in history. (One could illustrate this with regard to just about all our senses, not to bore folk with that now.)
That to me explaines most of the so-called "conflicting" evidence in this field, and the weary bleat that science and subjectivism will never meet. They actually have long ago, it just requires doing homework followed by a realistic insight.
Regards.
Thanks Colin.
.... and agreeing with you and Conrad, further adding:
The following does not necessarily refer to you guys, or anybody else that it does not refer to (now that is a profound statement!
). So preaching to the choir, but for completeness sake, some basic hearing philosophy:I have a problem with a certain view that in an almost derogatory way suggests that specs are allright, but there are still (as in must be) audible things that one cannot measure - ear so sensitive etc. This stance flatly ignores the multitude of tests done over decades at highly regarded centres (not by journalists) to try find out what is audible and what not. To the degree that this has resulted in reproduceable consistent results after using many thousands of subjects, I am really doubting that somewhere in some etherical spheres, something still lurks that we will discover or stand in awe of (re hearing, of course). Ergo, we have a useful "model" of the ear, even though we may not exactly be able to understand it from A - Z.
This is not elevating science arbitrarily; it is about as simple as finding, after enough tests, that a normal person is considered too intoxicated to drive a motor vehicle with a blood-alcohol content above 0,05%, to use an example. It is not that medicos and psychologists claim to be superior (or engineers), it is simply using test results the way science has used it in a million other cases. Science do not know everything, but it knows certain things. In that way I believe one can define that an amplifier will be blameless or otherwise. As said by you, program sources are something else now ..
It does become complex when one includes what was also found during the above tests, and that is the inconsistency in hearing interpretation. This is again not derogatory. Palaeontologists say that our hearing facility evolved as a warning facility. Appreciation of melodius sounds and that sort of music only "arrived" a few seconds before 12:00, on a scale of creation starting at midnight and noon being now. Ears did not evolve as distortion detectors; what exists is the way hearing happens to be and that is not necessary consistent with our terms, in this minute increment in history. (One could illustrate this with regard to just about all our senses, not to bore folk with that now.)
That to me explaines most of the so-called "conflicting" evidence in this field, and the weary bleat that science and subjectivism will never meet. They actually have long ago, it just requires doing homework followed by a realistic insight.
Regards.
Colin, I think you've summed up one of the major sticking points between two philosophies. Some (me included) believe that electrical signals between two components are the whole story, and that if signals are identical (to some level that we can all happily argue about), the resulting sound *must* be identical.
This is a really fundamental issue, because if identical signals produce different sounds, we have to resort to magic or unknown laws of physics to explain what's going on. I've simplified a bit, as the "signals" have to include what the ground level is doing, and things are never as easy as components floating in space, connected by exactly two wires, but the situation is still manageable.
We have the means (if you have the $$) to measure signals to a handful of parts per million, and I've yet to hear any rational claim that the ear can resolve that. I've also never heard of a blind test that's even hinted that things are not as I've described. What those tests do confirm is that very minor differences in level and frequency response are audible as quality differences.
IMO, cable interactions with component impedance's and component design (and, yes, capacitor choice) can easily alter those things. So, back to capacitors, if a particular type of cap (in a particular location) causes a tenth of a dB response difference (this is important- in the *system* that nobody ever seems to measure all at once) somewhere in the spectrum, you may well hear it. Worst, you'll (not you in particular) are apt to decide it's a difference in transparency, attack, smear, or some other emotion laden term that prevents getting at the truth of the matter.
IMO, the proper way to look at it is not to attribute "goodness" or "badness" to the caps, but to understand how the properties of different types interact with the surrounding circuitry. Since the same circuits turn up again and again, it's only reasonable that certain types of cap will be considered optimal in certain situations. It's also expected that some situations will be a compromise when a lot of capacitance combined with good properties is needed- out-of-the-loop coupling caps and the large AC-to-ground shunt capacitor in the feedback paths of many SS amps come to mind
Understand that I toss this stuff out with a fair amount of good humor. I understand that not everybody shares my views. I wear flameproof undergarments, but am also perfectly willing to change my mind when presented with evidence that doesn't require me to invoke magic or unknown physics- thus my current construction project of pure silver and other conductors to compare sonic differences.
This is a really fundamental issue, because if identical signals produce different sounds, we have to resort to magic or unknown laws of physics to explain what's going on. I've simplified a bit, as the "signals" have to include what the ground level is doing, and things are never as easy as components floating in space, connected by exactly two wires, but the situation is still manageable.
We have the means (if you have the $$) to measure signals to a handful of parts per million, and I've yet to hear any rational claim that the ear can resolve that. I've also never heard of a blind test that's even hinted that things are not as I've described. What those tests do confirm is that very minor differences in level and frequency response are audible as quality differences.
IMO, cable interactions with component impedance's and component design (and, yes, capacitor choice) can easily alter those things. So, back to capacitors, if a particular type of cap (in a particular location) causes a tenth of a dB response difference (this is important- in the *system* that nobody ever seems to measure all at once) somewhere in the spectrum, you may well hear it. Worst, you'll (not you in particular) are apt to decide it's a difference in transparency, attack, smear, or some other emotion laden term that prevents getting at the truth of the matter.
IMO, the proper way to look at it is not to attribute "goodness" or "badness" to the caps, but to understand how the properties of different types interact with the surrounding circuitry. Since the same circuits turn up again and again, it's only reasonable that certain types of cap will be considered optimal in certain situations. It's also expected that some situations will be a compromise when a lot of capacitance combined with good properties is needed- out-of-the-loop coupling caps and the large AC-to-ground shunt capacitor in the feedback paths of many SS amps come to mind
Understand that I toss this stuff out with a fair amount of good humor. I understand that not everybody shares my views. I wear flameproof undergarments, but am also perfectly willing to change my mind when presented with evidence that doesn't require me to invoke magic or unknown physics- thus my current construction project of pure silver and other conductors to compare sonic differences.
I think Colin and I have posted at the same time (in forum sense), and said somewhat the same thing.
So Colin, we can stand back-to-back; all the more difficult for folks to make an oblique attack!
Just referring to an article series on capacitor tests by Dr Cyril Bateman in EW toward the end of 2002. I found them excellent and quite extensive, also debunking a few urban legends. Might be on the net; I bought the magazine copies.
Regards.
So Colin, we can stand back-to-back; all the more difficult for folks to make an oblique attack!
Just referring to an article series on capacitor tests by Dr Cyril Bateman in EW toward the end of 2002. I found them excellent and quite extensive, also debunking a few urban legends. Might be on the net; I bought the magazine copies.
Regards.
Carlos,
Better late than never, I guess!!
You humble me; I don't much like this praise, it creates absurd expectations and I am just an ordinary man with an extraordinary compulsion to produce a better amp.
The world is made up of reasonable men and women. They work with what they have, and adapt to the world. Only the arrogant and overconfident will seek to change conventional thinking, and they generally work on ego or blind faith. They are the unreasonable ones, NP, JLH, Graham Maynard and Charles Ayre are amongst them.
Conrad,
You are absolutely right according to my research on Self. His amp reduces measureable distortion mechanisms and makes no pretensions about sonics. Yet sonics is where the focus clearly lies, with the gulf between objective measurements and subjective appreciation bigger than ever, even if the gap is measured in PERCEPTUAL terms. With so many low distortion amps sounding so ordinary in the market, I conclude that there are aspects of good sonic performance which are not yet being measured. I have heard the Blameless Self, and sadly it does not deliver as expected.
Johan,
Nothing that you don't all have, I assure you!! My private vision has always been of an amplifier that is musical and endearing, which makes a tear roll down your cheek...... This is hardly objective, and attracts howls of derision from the engineering dress circle..... BUT, it is necessary, as the finest engineering examples of good amplifiers leave much to be desired. If I have to stumble around in supernatural areas of the technology, mumbling incantations and groping for the ineffable, then so be it.... I do remain scientific and objective, however. I have had some success making engaging amps, so I feel pretty secure!
You mention capacitors, and the sonic characteristics they bring to amplifiers. I certainly agree. Recently I heard some teflon input caps on one of my preamps, and was absolutely astonished. They do make a difference, chiefly in resolution and smoothness. They actually sound 'natural', whatever that means. The price of admission is ridiculous, of course, but this has driven me to redesign the circuit for much higher input impedance so I can use a much smaller teflon cap, reasonably priced for manufacturing and thus saving almost $US160 for two channels. I'm yet to test this circuit, but it looks very promising.
Cheers,
Hugh
Better late than never, I guess!!
You humble me; I don't much like this praise, it creates absurd expectations and I am just an ordinary man with an extraordinary compulsion to produce a better amp.
The world is made up of reasonable men and women. They work with what they have, and adapt to the world. Only the arrogant and overconfident will seek to change conventional thinking, and they generally work on ego or blind faith. They are the unreasonable ones, NP, JLH, Graham Maynard and Charles Ayre are amongst them.
Conrad,
You are absolutely right according to my research on Self. His amp reduces measureable distortion mechanisms and makes no pretensions about sonics. Yet sonics is where the focus clearly lies, with the gulf between objective measurements and subjective appreciation bigger than ever, even if the gap is measured in PERCEPTUAL terms. With so many low distortion amps sounding so ordinary in the market, I conclude that there are aspects of good sonic performance which are not yet being measured. I have heard the Blameless Self, and sadly it does not deliver as expected.
Johan,
Nothing that you don't all have, I assure you!! My private vision has always been of an amplifier that is musical and endearing, which makes a tear roll down your cheek...... This is hardly objective, and attracts howls of derision from the engineering dress circle..... BUT, it is necessary, as the finest engineering examples of good amplifiers leave much to be desired. If I have to stumble around in supernatural areas of the technology, mumbling incantations and groping for the ineffable, then so be it.... I do remain scientific and objective, however. I have had some success making engaging amps, so I feel pretty secure!
You mention capacitors, and the sonic characteristics they bring to amplifiers. I certainly agree. Recently I heard some teflon input caps on one of my preamps, and was absolutely astonished. They do make a difference, chiefly in resolution and smoothness. They actually sound 'natural', whatever that means. The price of admission is ridiculous, of course, but this has driven me to redesign the circuit for much higher input impedance so I can use a much smaller teflon cap, reasonably priced for manufacturing and thus saving almost $US160 for two channels. I'm yet to test this circuit, but it looks very promising.
Cheers,
Hugh
AKSA said:
This is such ridiculous, self-congratulatory rubbish. A properly designed SS amplifier isn’t supposed to have a sound – it is supposed to faithfully reproduce the audio input signal without introducing perceptible coloration. A typical Douglas Self design (and those like it) satisfies this requirement by producing distortion well below perceptible limits.
I never cease to be amazed at the ridiculousness of the pseudoscientific claptrap rife with suppositions of magical “non-measurable distortion mechanisms” concocted for the express purpose of unjustifiably deriding other peoples design efforts by those trying to flog off their magically performing amplifiers – Concoctions predictably proffered with a less-than-humble serve of contrived emotionality in a lame attempt to compensate for the distinct lack of scientific or technical rationale.
Anyone out there who is reduced to tears by listening to their DIY amplifier suffers from a degree of emotional instability best treated by a professional.
But I guess that all those who haven’t seen the light need to throw out their perfectly OK, but spiritually-barren amplifier designs and rush out to buy an Aspen amplifier and share in the religious experience, because all those impeccably performing SS amplifiers don’t sound right because Hugh says so.
I used to own a Rotel and it didnt sound right, pretty basic low distortion 3 stage circuit,, the first 3 months I had it I thought it was the cats meow, but quickly I grew to realise it really sucked at playing music. Hugh has gone on to the next stage of aspen in designing an amplifier (lifeforce) which is apparently far more neutral but still sounds good. It seems to use concepts which are not found in your run of the mill HI-FI store offerings that should be used but unfortunately for our ears arent. Dougs Blameless is not plug and play and enjoy, instead it can be a beast thats needs a little taming so you can listen to it for more than 20 minute intervals. I guess the human ear can be a funny thing, a screen can tell you there is no fear, all should sound like magic, or atleast magic all above the vvanishing low distortion and noise floor but somehow it isnt so, atleast my ears dont tell me so, otherwise I would have loved the blameless right off the bat. Hugh speaks of capacitors and the sonic differences, doug self wrote very clearly on capacitor distortions namely electrolytic, but it applies to many others, which really comes down to dieletric absorbtion in signal coupling, no black magicl but pure fact that teflon has the lowest absorbtion of them all, aside from air..People like hugh spend years building with passion an amplifier that they can proudly release for the public to buy, most companies will just throw something together, pass it through accounting, and hope its approved by the penny watchers for the most part.
Colin
Colin
Glen, Andy,
Howls of derision indeed...... Why does this alleged 'claptrap' threaten you? You haven't heard my amps, you have not studied the schemat/layout, you won't be buying one, why does this distress you when there are dozens of blatant conjobs in this (and other) consumer fields?
If you knew the market, you would realise that specification on its own is not enough. Sound quality counts. Engagement is much talked about by audiophiles; clearly it matters. I don't believe you guys actually design and market amps into this market, so you are afforded the luxury of contempt for the commercial realities. Glen, you highlight measurements which bear little relationship to the extraordinary complexity of music, no consumer listens to test tones, and music can only be subjectively analysed. In any event, you do not know the distortion figures of my products, and I'm not about to go on about them anyway even though they are very good. There is a necessary balance here which from your ivory tower you choose to ignore.
Glen, if you should come to Melbourne, I would like to meet you. In fact, come to lunch on my ticket. I would like to hear your story, your outburst is interesting. If not, say so here and demonstrate your adversarial attitude for what it is.
Cheers,
Hugh
Howls of derision indeed......
Why does this alleged 'claptrap' threaten you? You haven't heard my amps, you have not studied the schemat/layout, you won't be buying one, why does this distress you when there are dozens of blatant conjobs in this (and other) consumer fields?If you knew the market, you would realise that specification on its own is not enough. Sound quality counts. Engagement is much talked about by audiophiles; clearly it matters. I don't believe you guys actually design and market amps into this market, so you are afforded the luxury of contempt for the commercial realities. Glen, you highlight measurements which bear little relationship to the extraordinary complexity of music, no consumer listens to test tones, and music can only be subjectively analysed. In any event, you do not know the distortion figures of my products, and I'm not about to go on about them anyway even though they are very good. There is a necessary balance here which from your ivory tower you choose to ignore.
Glen, if you should come to Melbourne, I would like to meet you. In fact, come to lunch on my ticket. I would like to hear your story, your outburst is interesting. If not, say so here and demonstrate your adversarial attitude for what it is.
Cheers,
Hugh
As a tradition (learned) i do not discuss with bad educated folks
People use hard agressive words to call atention...i think they can make a better work painting themselves red, holding a watter mellow over the head...dancing with bananas, and crossing some big street nude.
I use to put them into ignore list..as not kind enougth to listen them...noises...i prefer sound!
This means..he can jump and scream... i will not be reading..so..will not bother me....no chance for those guys!
regards,
Carlos
People use hard agressive words to call atention...i think they can make a better work painting themselves red, holding a watter mellow over the head...dancing with bananas, and crossing some big street nude.
I use to put them into ignore list..as not kind enougth to listen them...noises...i prefer sound!
This means..he can jump and scream... i will not be reading..so..will not bother me....no chance for those guys!
regards,
Carlos
Hey, this is an easy one. Put Crummycap in both channels. Feed both channels with music of your choice (parallel-mono). Feed output to speakers. Also feed outputs to matched pads and into something like an E-mu or other decent interface. Record a while at 96 or better khz and 24 bits. Match the levels. Compare waveforms. If they aren't close to identical go back to the drawing board because the channels aren't matched. You have bigger problems than capacitor types. If they are matched, put Teflon cap in one channel only. Run same test. If you see a difference in signals, you now have something legitimate to investigate. If not, the difference resides somewhere above the neck, below the hair, and between the ears, not in them. I don't know the answer here, but am quite confident it isn't magic, and it isn't some unknown signal property yet to be discovered (Nobel prize probably awaits you if it is). Hardware is hardware. It doesn't care about you, and you shouldn't get emotionally involved with it unless you want to get hurt 
Conrad,
I agree with you. BUT, the cost in time and effort of getting to the bottom of this conundrum is considerable. As a manufacturer, I'm only concerned with what sounds better, how to offer a competitive product, and how to trim costs. I actually can't afford to do this rather expensive research, and leave that to the academics with grants!!
I've heard the teflon caps, I can hear a profound improvement in resolution, I perceive there is a marketing advantage in having them, so I minimise their cost with optimal design and put 'em in the circuit. I note that the dielectric constant is lower than most anything else except air. That seems to compute in terms of 'memory', and might explain the sonic differences. Nuff said.....
On your last comment, above the neck/between the ears, I am bemused by the notion that different people hear different things, and a lot of people are suggestible. This is inescapable, and suggests that audio is like food, and automobiles. Not everyone likes the same thing; cf. tubes v. SS. Thus, we can identify a subjective, perceptual component as well as an objective measurement issue. Furthermore, testing in present technology (and specifically for the purpose of measuring THD) is only possible with either single or dual tones, and this is not a particularly valid facsimile of music, which is the definitive consumer working medium.
Cheers,
Hugh
I agree with you. BUT, the cost in time and effort of getting to the bottom of this conundrum is considerable. As a manufacturer, I'm only concerned with what sounds better, how to offer a competitive product, and how to trim costs. I actually can't afford to do this rather expensive research, and leave that to the academics with grants!!
I've heard the teflon caps, I can hear a profound improvement in resolution, I perceive there is a marketing advantage in having them, so I minimise their cost with optimal design and put 'em in the circuit. I note that the dielectric constant is lower than most anything else except air. That seems to compute in terms of 'memory', and might explain the sonic differences. Nuff said.....
On your last comment, above the neck/between the ears, I am bemused by the notion that different people hear different things, and a lot of people are suggestible. This is inescapable, and suggests that audio is like food, and automobiles. Not everyone likes the same thing; cf. tubes v. SS. Thus, we can identify a subjective, perceptual component as well as an objective measurement issue. Furthermore, testing in present technology (and specifically for the purpose of measuring THD) is only possible with either single or dual tones, and this is not a particularly valid facsimile of music, which is the definitive consumer working medium.
Cheers,
Hugh
Hugh, you're a businessman first, and that's the key to survival in a competitive market- my compliments! This is a guess, but there's probably a better market with better margins when amplifiers are sold using the language of poets, rather than the cold harsh realities of engineering. If you can lower the cost of using Teflon, you get the benefits of Teflon along with the bragging rights of using it. BTW, there's certainly nothing wrong with Teflon in technical terms
Now, looking at it from the technical end, I suggested the test routine I did because it's incredibly cheap and fast. No expensive gear beyond a $130 interface and the computer you probably already have. If you did the same thing with a scope, it would require an expensive differential front end, because the bare inputs probably don't have enough sensitivity or CM range for the gain you need.
From a business perspective, and this should be a good lesson for many people here, having that technical information as to why the Teflon cap is better (if, in fact, it is), doesn't offer you any benefit. It cost money to get the info and then what? It won't help sales. It won't drive the design. The measurement has a poor ROI.
Thus my happy situation of being a hobbyist. I don't have to worry about ROI, how to pay the employees, where to advertise, what the competition is doing. No expensive CE conducted and radiated emission tests. No vendors late with parts. I just worry about whether my wife approves of how much I spend and do what I like!
Now, looking at it from the technical end, I suggested the test routine I did because it's incredibly cheap and fast. No expensive gear beyond a $130 interface and the computer you probably already have. If you did the same thing with a scope, it would require an expensive differential front end, because the bare inputs probably don't have enough sensitivity or CM range for the gain you need.
From a business perspective, and this should be a good lesson for many people here, having that technical information as to why the Teflon cap is better (if, in fact, it is), doesn't offer you any benefit. It cost money to get the info and then what? It won't help sales. It won't drive the design. The measurement has a poor ROI.
Thus my happy situation of being a hobbyist. I don't have to worry about ROI, how to pay the employees, where to advertise, what the competition is doing. No expensive CE conducted and radiated emission tests. No vendors late with parts. I just worry about whether my wife approves of how much I spend and do what I like!
Re: Listener fatigue
Not sure that it is kosher to quote one's own stuff, but I feel somewhat like the angler suddenly washed off the rock, boots, fishing tackle, present scientific situation (I am only the messenger here, not the originator!), dignity and all. So pardon me for retrieving a wet paragraph or so in case someone did not notice before the wave came ......
I was carefully lifting my head above the speaker box after the previous salvo's (not seemed to have been aimed at me specifically - thanks for the consideration) - but:
Any over-selective argument in this business of audio is bound to run adry. Is it so difficult to understand that when e.g. Doug Self's amplifier does not sound right, that does not mean that there are things that scientists cannot yet measure? Why is it taboo to accept that natural, honest-to-life hearing perceptions can differ from one person to the next?? At least, I am confused; the previous sentence was in fact acknowledged during the salvo - why then is the immediate assumption (at least the way I "heard" it) that science still cannot account for all? I find those two truths contradictory - in fact, my above quote shows that science can account for this, that is why some folks will dislike the same setup that others prefer!
Hugh (and I stand by my earlier recognition of your achievements among that of many others) you say that some amplifiers with good specs sound poor - well ordinary, whatever.
What "good" specs?
I will now rear up my whole person from behind my loudspeaker box (as you know, the present sizes do not provide as much protection as did the Klipsch's of old anyway!) and say: Indeed no! One is in fact able to explain most of an amplifier's audible shortcomings by looking at proper specs - only those must include at least also a spectrum analysis into a resistor as well as into a (again proper) loudspeaker simulated load. We are a little starved re magazines down here in South Africa, but in the only mag we find here with analyses viz. Stereophile, I see that correlation most of the times.
I make amplifiers for a "market" - i.e. not large production runs, but at least for a variety of clients - all with different hearing (and loudspeakers and CD players and ... and....). For whose "taste" must I design? Perhaps so far I was fortunate in that nobody was disappointed. But either I must have a singular talent thataway (and I don't believe that), or I must have done something right by simply following basics plus what little experience several decades (5 of them) have earned me.
I am trying to make the point that one cannot justifiably condemn something because it did not sound right to someone - or 2 or 3 or even 10 people. My minimum requirement for such a claim would be a proper blind test. (And that is another sticky toffee of a whole new argument. For now, listening to unknown entities repeatedly does not constitute a valid blind test; not on one occasion or in one day or two.) Similarly it does not mean that you are hearing challenged if you are incapable of hearing what the next man does (sorry, that one is too easy!). Coming to a valid conclusion with hearing tests is a technology in itself, involving knowledge of hearing physiology and psychology. The tests and pronouncements of the studies quoted above involved all of that, which is why they are considered representative.
This does of course not mean that one cannot step into a shop and prefer something - it is your ears, time and money and it (mostly) works. It does mean that one must be careful of elevating that to dogma.
Thanks for attention.
Johan Potgieter said:
Not sure that it is kosher to quote one's own stuff, but I feel somewhat like the angler suddenly washed off the rock, boots, fishing tackle, present scientific situation (I am only the messenger here, not the originator!), dignity and all. So pardon me for retrieving a wet paragraph or so in case someone did not notice before the wave came ......
I was carefully lifting my head above the speaker box after the previous salvo's (not seemed to have been aimed at me specifically - thanks for the consideration) - but:
Any over-selective argument in this business of audio is bound to run adry. Is it so difficult to understand that when e.g. Doug Self's amplifier does not sound right, that does not mean that there are things that scientists cannot yet measure? Why is it taboo to accept that natural, honest-to-life hearing perceptions can differ from one person to the next?? At least, I am confused; the previous sentence was in fact acknowledged during the salvo - why then is the immediate assumption (at least the way I "heard" it) that science still cannot account for all? I find those two truths contradictory - in fact, my above quote shows that science can account for this, that is why some folks will dislike the same setup that others prefer!
Hugh (and I stand by my earlier recognition of your achievements among that of many others) you say that some amplifiers with good specs sound poor - well ordinary, whatever.
What "good" specs?
I will now rear up my whole person from behind my loudspeaker box (as you know, the present sizes do not provide as much protection as did the Klipsch's of old anyway!) and say: Indeed no! One is in fact able to explain most of an amplifier's audible shortcomings by looking at proper specs - only those must include at least also a spectrum analysis into a resistor as well as into a (again proper) loudspeaker simulated load. We are a little starved re magazines down here in South Africa, but in the only mag we find here with analyses viz. Stereophile, I see that correlation most of the times.
I make amplifiers for a "market" - i.e. not large production runs, but at least for a variety of clients - all with different hearing (and loudspeakers and CD players and ... and....). For whose "taste" must I design? Perhaps so far I was fortunate in that nobody was disappointed. But either I must have a singular talent thataway (and I don't believe that), or I must have done something right by simply following basics plus what little experience several decades (5 of them) have earned me.
I am trying to make the point that one cannot justifiably condemn something because it did not sound right to someone - or 2 or 3 or even 10 people. My minimum requirement for such a claim would be a proper blind test. (And that is another sticky toffee of a whole new argument. For now, listening to unknown entities repeatedly does not constitute a valid blind test; not on one occasion or in one day or two.) Similarly it does not mean that you are hearing challenged if you are incapable of hearing what the next man does (sorry, that one is too easy!). Coming to a valid conclusion with hearing tests is a technology in itself, involving knowledge of hearing physiology and psychology. The tests and pronouncements of the studies quoted above involved all of that, which is why they are considered representative.
This does of course not mean that one cannot step into a shop and prefer something - it is your ears, time and money and it (mostly) works. It does mean that one must be careful of elevating that to dogma.
Thanks for attention.
Johan, I feel your pain, as our standards appear the same, as do our decades 
Hugh, however, is selling sizzle, not steak. Hopefully his steak lives up to the advertising, but he's astute enough to realize that selling sizzle is more profitable, gives him more control over the customers perception, and avoids the need for academic research that he'll never get a return out of. I don't see this as a terrible thing, only a choice in priorities. IMO, most of the high-end makers use a similar business model, whether they'll admit it or not. If customers believe in magic, and buying this stuff makes them happy, great. For those of us that understand how various bits and pieces of varying impedance interact, and accept the absolute equivalence of the time and frequency domain viewpoints, not to mention decades of properly conducted audio tests, and who want designs backed up by science, diy is probably the best choice.
Hugh, however, is selling sizzle, not steak. Hopefully his steak lives up to the advertising, but he's astute enough to realize that selling sizzle is more profitable, gives him more control over the customers perception, and avoids the need for academic research that he'll never get a return out of. I don't see this as a terrible thing, only a choice in priorities. IMO, most of the high-end makers use a similar business model, whether they'll admit it or not. If customers believe in magic, and buying this stuff makes them happy, great. For those of us that understand how various bits and pieces of varying impedance interact, and accept the absolute equivalence of the time and frequency domain viewpoints, not to mention decades of properly conducted audio tests, and who want designs backed up by science, diy is probably the best choice.
HI Johan,
Hmmm. Tough questions. I don't have a lot of time to spend answering this kind of rigor, because there's no ROI and I'm kinda busy at present, but here goes.
Any amp with 20Hz-20KHz +/-1dB and THD of less than 0.05% at full power into 8R would classify as good specs.
THD takes no account of spectral distribution of that distortion, of course, and there's the rub.
Frequency response is clearly important for anything with wide bandwidth pretensions.
Yet, most of Japanese amps of the last twenty years meet these specs, and more, but sound, well, a little lifeless, lacking somehow in vitality. Lux is better than most, but even the big Denon monoblocs were dull, at least to me. Same for the Self Blameless I heard at an audio club. There was none of this lifeless sound with the single ended triodes I've heard.
I attribute this lifeless sound to over compensation, in an attempt to make the amp unconditionally stable into any load, no matter how nasty. I would not blame any designer for this approach; there are some truly horrible crossovers out there which dip below two ohms and create huge phase shift. It turns out that designing for any load is one of the reasons why many Class AB SS amps don't sound so good, but I won't comment further on this; the topic is complicated and consumes a lot of time.
Johan, you ask for chapter and verse on the proof of this argument. I can't give it to you. It's an ingrained hunch I have based on my work with amps over many decades. I'm no longer much interested in a formal proof now, I just know what works and what does not. I do like single ended design, don't much go for full complementary input stages or voltage amps. Amongst the designs I see which show conventional engineering rigor I do notice the same old approach which has not changed in decades, and only masters like NP and Charles Hansen, of Ayre amps, seem to have it right. Tube amps are very different, and the conventional designs I see plastered all over the web mostly sound very good. I also think that NFB is just fine, and gets a very bad rap. It's difficult to design a good amp without it, though the Dartzeil seems pretty good from all reports.
I hear your comment that this is all very hit and miss. But so is the choice of a good restaurant, or digital camera, or automobile. They are all products of perception; taste varies, and there's no accounting for it. Some love the surgical, dry, high impact of SS, others prefer the organic mellow sound of tubes. Why? Heck, I dunno, but it does represent a legitimate choice, and there will be quite measureable portions of the consuming audiophile public who choose them, and that's really all there is to it. Psycho-acoustics can give us some of the answers, but not all...... and there is the psychology of the marketing to consider - what ageing, wealthy audiophile can resist a picture of the patrician Dan standing next to his Testarossa with his technically perfect amp at his feet? It's a very comely image, and it sells a lot of amps.
In closing, don't forget fashion. One year it's zero global feedback, the next it's tubes, the next it's teflon couplers, and so it goes on. An impassioned, even feverish audio press can whip up a frenzy of excitement over the latest gadget, we would all be cynical if we sat in the planning rooms of the advertising agencies and editorial discussions at the audiophile magazines!
But that's all normal in a sophisticated consumer world. Every dog has his day, but only a very small number really do know the truth, and they are not generally the contemporary buying public. Example: I drive a 15 year old car in very good condition, a Cressida, because they represent the best Toyota could make back then and even the newest models, with the exception of the Lexus range, can't compete with the excellence available in the early nineties in what was a very expensive car but which is now dirt cheap. I mention this because I represent an insignificant portion of the auto market and my decision to keep this very old model is not important to the present market, but it is an informed choice, and it represents - to me anyway - the truth.
The same could be said of say the JLH 10W Class A amplifier. An oldy, but a goody.....
Cheers,
Hugh
Hmmm. Tough questions. I don't have a lot of time to spend answering this kind of rigor, because there's no ROI and I'm kinda busy at present, but here goes.
Any amp with 20Hz-20KHz +/-1dB and THD of less than 0.05% at full power into 8R would classify as good specs.
THD takes no account of spectral distribution of that distortion, of course, and there's the rub.
Frequency response is clearly important for anything with wide bandwidth pretensions.
Yet, most of Japanese amps of the last twenty years meet these specs, and more, but sound, well, a little lifeless, lacking somehow in vitality. Lux is better than most, but even the big Denon monoblocs were dull, at least to me. Same for the Self Blameless I heard at an audio club. There was none of this lifeless sound with the single ended triodes I've heard.
I attribute this lifeless sound to over compensation, in an attempt to make the amp unconditionally stable into any load, no matter how nasty. I would not blame any designer for this approach; there are some truly horrible crossovers out there which dip below two ohms and create huge phase shift. It turns out that designing for any load is one of the reasons why many Class AB SS amps don't sound so good, but I won't comment further on this; the topic is complicated and consumes a lot of time.
Johan, you ask for chapter and verse on the proof of this argument. I can't give it to you. It's an ingrained hunch I have based on my work with amps over many decades. I'm no longer much interested in a formal proof now, I just know what works and what does not. I do like single ended design, don't much go for full complementary input stages or voltage amps. Amongst the designs I see which show conventional engineering rigor I do notice the same old approach which has not changed in decades, and only masters like NP and Charles Hansen, of Ayre amps, seem to have it right. Tube amps are very different, and the conventional designs I see plastered all over the web mostly sound very good. I also think that NFB is just fine, and gets a very bad rap. It's difficult to design a good amp without it, though the Dartzeil seems pretty good from all reports.
I hear your comment that this is all very hit and miss. But so is the choice of a good restaurant, or digital camera, or automobile. They are all products of perception; taste varies, and there's no accounting for it. Some love the surgical, dry, high impact of SS, others prefer the organic mellow sound of tubes. Why? Heck, I dunno, but it does represent a legitimate choice, and there will be quite measureable portions of the consuming audiophile public who choose them, and that's really all there is to it. Psycho-acoustics can give us some of the answers, but not all...... and there is the psychology of the marketing to consider - what ageing, wealthy audiophile can resist a picture of the patrician Dan standing next to his Testarossa with his technically perfect amp at his feet? It's a very comely image, and it sells a lot of amps.
In closing, don't forget fashion. One year it's zero global feedback, the next it's tubes, the next it's teflon couplers, and so it goes on. An impassioned, even feverish audio press can whip up a frenzy of excitement over the latest gadget, we would all be cynical if we sat in the planning rooms of the advertising agencies and editorial discussions at the audiophile magazines!
But that's all normal in a sophisticated consumer world. Every dog has his day, but only a very small number really do know the truth, and they are not generally the contemporary buying public. Example: I drive a 15 year old car in very good condition, a Cressida, because they represent the best Toyota could make back then and even the newest models, with the exception of the Lexus range, can't compete with the excellence available in the early nineties in what was a very expensive car but which is now dirt cheap. I mention this because I represent an insignificant portion of the auto market and my decision to keep this very old model is not important to the present market, but it is an informed choice, and it represents - to me anyway - the truth.
The same could be said of say the JLH 10W Class A amplifier. An oldy, but a goody.....
Cheers,
Hugh
IMO, two amps that met 20-20k +/- 1 dB, would be perceived very differently if the response curves had opposite slopes or some other peculiar mismatch- a 2 dB wide window allows for a lot of creativity in giving an amp a particular sound- something the wise high-end designer would take subtle advantage of.
Like him or hate him, remember that Carver was able to successfully match the sound of any amp in blind tests using a few (or a lot of) tweeks.
Regards,
CH
Like him or hate him, remember that Carver was able to successfully match the sound of any amp in blind tests using a few (or a lot of) tweeks.
Regards,
CH
Conrad,
You mentioned that I sell sizzle, not steak. A fetching metaphor, but I cannot let it go as it is wide of the mark. Have a look at my forum and read some of the unsolicited reviews and critiques of my gear (I am assuming you've not heard or seen it!) and understand that I distinctly am NOT selling sizzle. I am selling performance, in fact, but while my techniques for achieving this performance do not necessarily correspond to your research oriented approach, it would be inappropriate to dismiss it as wrong, or failing to deliver results.
As I've said before, you do have an obligation to listen before making judgements....
Cheers,
Hugh
You mentioned that I sell sizzle, not steak. A fetching metaphor, but I cannot let it go as it is wide of the mark. Have a look at my forum and read some of the unsolicited reviews and critiques of my gear (I am assuming you've not heard or seen it!) and understand that I distinctly am NOT selling sizzle. I am selling performance, in fact, but while my techniques for achieving this performance do not necessarily correspond to your research oriented approach, it would be inappropriate to dismiss it as wrong, or failing to deliver results.
As I've said before, you do have an obligation to listen before making judgements....
Cheers,
Hugh
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