I think you were referring to his Proceeding Paper; afair he didn´t say, that it is impossible in general to get a periodic signal from a DAC, but was pointing to a well known property of dicrete time signals, that has to be taken into account when synthesize waveforms.
More a reminder why it is sometimes not sufficient to use a soundcard for the generation to test waveforms, because without `special´ algorithms the waveform may contain additional unwanted spectral content due to the periodicity problem.
What do you mean by that?
In any case, the recording sounded very good for being so old and recorded on such 'primitive equipment'. As far as analog audio is concerned, there are lots of areas capable of discussion, such as: passive vs active preamps, buffers, complexity vs simplicity, etc., etc. . Digital sound quality problems and solutions are also quite interesting in this context, since digital is the primary medium used today.
Two different designs. One SS the other glow Fet. The response similar and low noise floors on both. The feedback was about about 20 dB in both cases. The point being one had distortion an order of magnitude higher. I would say nothing new here but both were very good. Speakers 100 dB also.
So what can we measure? John is quite correct to use known good components and they are audible but what can we measure to move forward?
John,
This is bound to happen, this wandering.
If I may take a step back on all of this and give my own view on what we need to do to build better audio electronics? Thank you for the indulgence, Gentlemen.
If we wish to build "better" audio electronics we first must define clearly what is "better".
Some would argue that "better" means better in the traditional measurements hat are being promoted. The fallacy of this should be patently obvious and should need no explanation. As one example, Speakers are almost never characterised for distortion, because the levels of distortion in a speaker at rated power are extremely gross, yet for Amplifiers very low THD is promoted as measure of quality, clearly a case of straining at Gnats and swallowing the camel.
Others would argue that "better" means better in terms of how people react to the reproduced sound. On the surface this makes immense sense, in fact, it makes ABSOLUTE sense, as both recordings of music and equipment to play them back exist solely for purpose of human sensual and aesthetic enjoyment.
Thus if something measures perfect in terms of traditional measurements but fails to provide sensual and aesthetic enjoyment of music to those who listen to results, it is by ABSOLUTE definition BAD, as it is unfit for the purpose.
Where problems come in is that it seems to have so far not been possible to translate "better sound" into simple measurements that yield simple "figures of merit" so an engineer can say "if this number reads 10 it is "perfect" and can work towards making this number read as close to 10 as he can.
So one side uses false yardsticks, the other has no "true yardsticks" of their own. In fact, many attempts have been made over time to correct this, yet they have been met mostly with shrugs and with derision from some quarters. The result is that very little real progress has been made, mostly because the nature of the problems is insufficiently clear and the very real problems are by far too rarely accepted as real problems.
For example, back in the mid-90's I proposed an approach to a speaker which would be able to correct for the speakers various flaws (including HD, IMD, Power Compression and others) by "pre-distorting" the signals fed to each driver, even including the room (this was on the bass list), with an outline of the needed calibration routines, required DSP funtions etc. There was zero interest, as distortion and compression in speakers where just not perceived as valid problem that needs solving and a decade and a halve later there is still no interest.
So, to make any progress it is necessary to abolish the blinders many in audio engineering are wearing, to abandon the blind faith into "revealed truth" that cannot be altered and to stop attacking, in order to silence, anything and anyone who seems to question this "revealed truth", which is often enough to say "almost completely" not backed by empirical studies into efficacy.
However, as long as it remains easier to deny the truth and ostracise, ridicule and wherever possible censor dissenting views and ideas, this will simply not happen and things will continue as they are. A stalemate on a battlefield of mediocracy, long abandoned by the more able and competent generals and officers for fields offering more glory and pay. In fact it is much like Stanislaw Lem's description of the state of affairs in the (fictional) sciences of the (fictional) planet Solaris in his (science fiction) book of the same name, despite the absolutely stunning revelations that the planet yet had to yield...
When I was younger, less wise and more foolish, this state of affairs may have induced me to try to illustrate the situation and to try to stir up this dreary bog of sullen prejudice and muddy inertia which some call "common sense".
Good thing I'm not, or I could really get into trouble with the powers that be, innit?
Ciao T
This is bound to happen, this wandering.
If I may take a step back on all of this and give my own view on what we need to do to build better audio electronics? Thank you for the indulgence, Gentlemen.
If we wish to build "better" audio electronics we first must define clearly what is "better".
Some would argue that "better" means better in the traditional measurements hat are being promoted. The fallacy of this should be patently obvious and should need no explanation. As one example, Speakers are almost never characterised for distortion, because the levels of distortion in a speaker at rated power are extremely gross, yet for Amplifiers very low THD is promoted as measure of quality, clearly a case of straining at Gnats and swallowing the camel.
Others would argue that "better" means better in terms of how people react to the reproduced sound. On the surface this makes immense sense, in fact, it makes ABSOLUTE sense, as both recordings of music and equipment to play them back exist solely for purpose of human sensual and aesthetic enjoyment.
Thus if something measures perfect in terms of traditional measurements but fails to provide sensual and aesthetic enjoyment of music to those who listen to results, it is by ABSOLUTE definition BAD, as it is unfit for the purpose.
Where problems come in is that it seems to have so far not been possible to translate "better sound" into simple measurements that yield simple "figures of merit" so an engineer can say "if this number reads 10 it is "perfect" and can work towards making this number read as close to 10 as he can.
So one side uses false yardsticks, the other has no "true yardsticks" of their own. In fact, many attempts have been made over time to correct this, yet they have been met mostly with shrugs and with derision from some quarters. The result is that very little real progress has been made, mostly because the nature of the problems is insufficiently clear and the very real problems are by far too rarely accepted as real problems.
For example, back in the mid-90's I proposed an approach to a speaker which would be able to correct for the speakers various flaws (including HD, IMD, Power Compression and others) by "pre-distorting" the signals fed to each driver, even including the room (this was on the bass list), with an outline of the needed calibration routines, required DSP funtions etc. There was zero interest, as distortion and compression in speakers where just not perceived as valid problem that needs solving and a decade and a halve later there is still no interest.
So, to make any progress it is necessary to abolish the blinders many in audio engineering are wearing, to abandon the blind faith into "revealed truth" that cannot be altered and to stop attacking, in order to silence, anything and anyone who seems to question this "revealed truth", which is often enough to say "almost completely" not backed by empirical studies into efficacy.
However, as long as it remains easier to deny the truth and ostracise, ridicule and wherever possible censor dissenting views and ideas, this will simply not happen and things will continue as they are. A stalemate on a battlefield of mediocracy, long abandoned by the more able and competent generals and officers for fields offering more glory and pay. In fact it is much like Stanislaw Lem's description of the state of affairs in the (fictional) sciences of the (fictional) planet Solaris in his (science fiction) book of the same name, despite the absolutely stunning revelations that the planet yet had to yield...
When I was younger, less wise and more foolish, this state of affairs may have induced me to try to illustrate the situation and to try to stir up this dreary bog of sullen prejudice and muddy inertia which some call "common sense".
Good thing I'm not, or I could really get into trouble with the powers that be, innit?
Ciao T
And what has improved since 100 years ago? Pavel mentioned two items. Every yardstick starts at zero even if it is not marked.
Everything you can measure is probably thousands of times better, but is the best modern reproduction a thousand times better.
Well, hundreds, anyway. Hugely better than when I was a youngster, and that was less than half a century ago.
Tony: But if you played it back with the best equipment of 1956 versus now? 
Actually, if they were still alive, you could make a far more realistic sounding recording now than you could then. The colorations from the mikes and studio electronics (not to mention the noise) are attractive and still sought after. But we can make things far more neutral these days, if that's what we want to do. I wish more engineers/producers thought that way...
Actually, if they were still alive, you could make a far more realistic sounding recording now than you could then. The colorations from the mikes and studio electronics (not to mention the noise) are attractive and still sought after. But we can make things far more neutral these days, if that's what we want to do. I wish more engineers/producers thought that way...
Agreed. I have it as well and it is one of my favorites. I also agree with John regarding sound quality of some jazz recordings from the early sixties. Attempts to digitize them kill the original natural sound.
This is the HEART of the matter PMA and Thorsten. We have to address the issues from microphone to speaker to get the same 'emotion' or 'reality' from a recorded performance. Is it because of tubes, and their attendant transformers? Is it because class A was standard, and non-operational amplifier type circuits were used? Is it because they didn't use digital at all, even hidden digital, such as a preview digital delay for record recording? Is it because they tried their very best, with no excuses, to make the best sound possible? These are the important questions, not some spec..
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