I found some graphs made more than 40 years ago, made while I was working on the film sound track of the movie 'Fillmore'. These were part of my talk at an AES convention 40 years ago. Note that it was not easy to get it right.
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We have discussed a lot of topics that are not really 'hi end audio' lately. Some are old, pro audio, from my files, others perhaps, not even audio. Some here seem to imply that new audio design for better quality is 'dead', because either the pinnacle has been reached and we need no better at any price or effort, or nobody really cares, anyway.
I do not agree with these conclusions.
However, to actually know whether audio can improve, we have to know the limitations of what we have. This includes limitations in microphones, recording and reproduce electronics, digital artifacts, and the fundamental limitations in loudspeaker design, no matter what the size or cost, with any given approach.
Just like with automobiles and the like, if we are truly happy with what we have, then WHY change it?
For example, why do automobiles have so much horsepower, these days? I got along with 32hp, for 5 years in my Renault Dauphine. Who needs more? And if more, how much more? Think what kind of gas milage we could get today, IF we only wanted an engine to put out 32hp, on a good day, with fuel injection, etc.
We all know that it is relatively absurd to just have 32 hp, today, but it is doable and still go highway speeds. To me, audio is much the same.
We can get MP3 today and use either earphones or some powered loudspeakers and get some music. Is that ALL we want? If so, then I am wasting my time.
However, I am hoping that some still want significantly more, will keep an open mind about the past, even if they were only little or not even born yet, when certain classic recordings were made, that serious audio engineers knew what they were doing, and in doing their best, made a 'classic' for virtually all time, even if their recording methods seem primitive to engineers, today. At the same time, keeping an open mind of the intrinsic limitations of digital, especially 'practical' or cost effective digital, and ignore the call of 'Perfect sound, forever' because it is not necessarily so, not yet.
Let's look into what we can do to make things better in audio quality.
I do not agree with these conclusions.
However, to actually know whether audio can improve, we have to know the limitations of what we have. This includes limitations in microphones, recording and reproduce electronics, digital artifacts, and the fundamental limitations in loudspeaker design, no matter what the size or cost, with any given approach.
Just like with automobiles and the like, if we are truly happy with what we have, then WHY change it?
For example, why do automobiles have so much horsepower, these days? I got along with 32hp, for 5 years in my Renault Dauphine. Who needs more? And if more, how much more? Think what kind of gas milage we could get today, IF we only wanted an engine to put out 32hp, on a good day, with fuel injection, etc.
We all know that it is relatively absurd to just have 32 hp, today, but it is doable and still go highway speeds. To me, audio is much the same.
We can get MP3 today and use either earphones or some powered loudspeakers and get some music. Is that ALL we want? If so, then I am wasting my time.
However, I am hoping that some still want significantly more, will keep an open mind about the past, even if they were only little or not even born yet, when certain classic recordings were made, that serious audio engineers knew what they were doing, and in doing their best, made a 'classic' for virtually all time, even if their recording methods seem primitive to engineers, today. At the same time, keeping an open mind of the intrinsic limitations of digital, especially 'practical' or cost effective digital, and ignore the call of 'Perfect sound, forever' because it is not necessarily so, not yet.
Let's look into what we can do to make things better in audio quality.
The first thing to come to mind is WHY I chose to direct couple audio circuits, where I possibly can, and when I can't, I try to use the best caps possible for the application. This is MORE expensive than using the cheapest caps that will allow the amp or preamp meet 'spec'. (more later)
Hi John,
its been a long time since I wrote but i was never completely out of audio - still doing it. Now I am old and retired and can give back/away as you are doing. can I suggest that the two area in most need of improvement is still at the front end and at the tail end. Would you discuss the mic/mic preamps and/or ADC and also the speaker/amp interface issues. As that seems to me as areas in great need of improvement. Though speaker design is not what we are dealing with here - it is still pretty awful in most cases. Thx for giving your input for others to grow from as their stepping stone. I hope to do same where I can --RNMarsh (Dick Marsh to you).
its been a long time since I wrote but i was never completely out of audio - still doing it. Now I am old and retired and can give back/away as you are doing. can I suggest that the two area in most need of improvement is still at the front end and at the tail end. Would you discuss the mic/mic preamps and/or ADC and also the speaker/amp interface issues. As that seems to me as areas in great need of improvement. Though speaker design is not what we are dealing with here - it is still pretty awful in most cases. Thx for giving your input for others to grow from as their stepping stone. I hope to do same where I can --RNMarsh (Dick Marsh to you).
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High end audio is really wonderfull at 3146 euros /kg....
14000 euros for a phono tube preamp , i guess that even JCurl will fall
from his casual armchair....
Nagra PL-P
14000 euros for a phono tube preamp , i guess that even JCurl will fall
from his casual armchair....
An externally hosted image should be here but it was not working when we last tested it.
Nagra PL-P
I didnt know they also make amplifiers.
Seems that at 13000$/pair the monoblocks amps are just
a league below in matter of rip off..
0.5 to 0.7% THD for about 40W rms.....
Nagra VPA monoblock power amplifier Measurements | Stereophile.com
Seems that at 13000$/pair the monoblocks amps are just
a league below in matter of rip off..
0.5 to 0.7% THD for about 40W rms.....
Nagra VPA monoblock power amplifier Measurements | Stereophile.com
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I recently heard a system in the 80 thousand dollar neighborhood, at a very nice high end store. The components were Ayre and Wilson, and another, and it was nice sound, but didn't touch my own system in sound quality.
Personal taste and room setup make such a difference that spending the big bucks just isn't worth it in my opinion. It was probably setup to the tastes of the people there, and it sounded good just not really great. I'm not knocking the components, just saying you don't need to spend crazy money to experience really great sound. Pay attention to component matching, room acoustics, speaker setup, and you may come up with something that you may like even better.
Personal taste and room setup make such a difference that spending the big bucks just isn't worth it in my opinion. It was probably setup to the tastes of the people there, and it sounded good just not really great. I'm not knocking the components, just saying you don't need to spend crazy money to experience really great sound. Pay attention to component matching, room acoustics, speaker setup, and you may come up with something that you may like even better.
john curl said:
I call it habituation. It does take time to get used to a new sound, and really evaluate it. If I had that equipment in our home to set up myself perhaps I'd feel different after a longer audition, or not. I don't know.
When I've had lesser systems, I could easily find fault with it when listening to the higher end stuff at audio stores.
I'm just pointing out that you don't need to spend the mega bucks to get great sound, if you take lots of care in setting up your room and system. It took a lot of time to get our system to sound that good.
I would like to clarify my point.
A few years ago, I attended a CES where I heard a number of systems. I heard some very good ones, usually with tube electronics, AND I heard some very fair, but not perfect sounding ones, even from the people I was working for, even if they had my own amps and preamps, sometimes playing. Later in the week, I came home, turned on my own PERSONAL audio system and was very satisfied.
Yet, even though I have a fair amount of money invested in my system, I have not changed anything for about 10 years, except for a phono cartridge. If I bring another audiophile, like Jack Bybee, for instance, to listen to my system, for some reason, he is very uncomfortable, because he does not think much of it. And he is correct to a point, because I do NOT maintain my system or update it continually. I could improve it, but I am either too lazy or too 'broke' to invest in it to make it a 'showpiece'.
Now, where have I heard examples, locally, of a really good sound system, that is not my own? I can name just two in the Bay Area over the last 25 years.
One, was at Dave Wilson's house, when he lived in the area, with the WAMM system that he used to demo for his clients.
The second was at an eye doctor's house in the Oakland hills that is worth about 1/3 million dollars or so. He is always upgrading his system, and it shows.
I once went to Jack Bybee's house and thought his system 'fair', I felt the same about Brian Cheney's (VMPS) set-up. I, too, am apparently hard to please, except I can come home and listen, for the most part, to my personal system and be reasonably happy. Yet it needs a lot of work, especially updating, as well as adjustment.
This is why I don't trust personal comparisons between home and other peoples audio systems. I have come to realize that I 'forgive' my own audio system for its faults and 'listen through' to the music, but I am not so forgiving with other audio systems, and they had better be extraordinary to sound, to me, as good as my own.
A few years ago, I attended a CES where I heard a number of systems. I heard some very good ones, usually with tube electronics, AND I heard some very fair, but not perfect sounding ones, even from the people I was working for, even if they had my own amps and preamps, sometimes playing. Later in the week, I came home, turned on my own PERSONAL audio system and was very satisfied.
Yet, even though I have a fair amount of money invested in my system, I have not changed anything for about 10 years, except for a phono cartridge. If I bring another audiophile, like Jack Bybee, for instance, to listen to my system, for some reason, he is very uncomfortable, because he does not think much of it. And he is correct to a point, because I do NOT maintain my system or update it continually. I could improve it, but I am either too lazy or too 'broke' to invest in it to make it a 'showpiece'.
Now, where have I heard examples, locally, of a really good sound system, that is not my own? I can name just two in the Bay Area over the last 25 years.
One, was at Dave Wilson's house, when he lived in the area, with the WAMM system that he used to demo for his clients.
The second was at an eye doctor's house in the Oakland hills that is worth about 1/3 million dollars or so. He is always upgrading his system, and it shows.
I once went to Jack Bybee's house and thought his system 'fair', I felt the same about Brian Cheney's (VMPS) set-up. I, too, am apparently hard to please, except I can come home and listen, for the most part, to my personal system and be reasonably happy. Yet it needs a lot of work, especially updating, as well as adjustment.
This is why I don't trust personal comparisons between home and other peoples audio systems. I have come to realize that I 'forgive' my own audio system for its faults and 'listen through' to the music, but I am not so forgiving with other audio systems, and they had better be extraordinary to sound, to me, as good as my own.
My stereo setup costs about $60,000 and I'm quite pleased with it, though I know what I'd like to change in it, should I have the money for it (winning the lottery is probably the only way I'll have that money, though statistically there are more chance I'll be run down by a train… ). I didn't like most setups of others audiophiles I heard, which is to indicate once again how much it is given to individual taste and preferences. What amazes me is how little, if any at all, some audiophiles spend on acoustic treatment, which is essential for good sound, even for decent sound.
Well said Joshua. Now I will go to the topic of capacitors in audio equipment.
One will find that coupling capacitors are still very 'popular' in mid-fi equipment, even from lower priced Parasound products. These capacitors 'simplify' circuit design by removing the need for servos or precise offset matching, and often allows single voltages to be used for the power supply. This design technique isolates individual stages and makes them more 'fool proof'.
It will normally be found that removing coupling caps will make better sounding equipment, but it will be more difficult to make work consistently. The reasons for more difficulty is either the inclusion of servos, a dual supply, or extremely well matched input devices or higher quality IC's with very low offset.
Now WHY are capacitors a problem in the first place?
First a little history:
Back in the 1960's we made most audio products with a single power supply, with input and output capacitors, at a minimum. Usually we also had interstage capacitors, as well. To save space, we used tantalum caps that were polarized, and they almost always had some DC voltage across them, because of the single supply used, almost exclusively at that time. This was actually a small advantage that there was some DC bias on the polarized caps, but we did not necessarily know that at the time. It is one of the reasons that a tape recorder like the Revox A77 could sound pretty good, even by today's standards.
However, by 1970, we were trying to introduce dual supplies for both amps and preamps, and usually in the preamp case, in order to use IC's. This presented a problem with using the polarized caps, because they could be biased, either statically(DC) or dynamically in the wrong direction. What to do? We could not use Mylar or polystyrene caps, because they were just too large for the circuit space. Sometimes we used CERAMIC coupling caps, that were available in values up to 2 uf or so. Also, if we thought we could get away with it, we used tantalum caps in the feedback loop, and direct coupled the input and output. We felt that we had made the best 'compromise' possible, a single tantalum cap per stage (even though the cap had little or no DC voltage across it).
(more later)
One will find that coupling capacitors are still very 'popular' in mid-fi equipment, even from lower priced Parasound products. These capacitors 'simplify' circuit design by removing the need for servos or precise offset matching, and often allows single voltages to be used for the power supply. This design technique isolates individual stages and makes them more 'fool proof'.
It will normally be found that removing coupling caps will make better sounding equipment, but it will be more difficult to make work consistently. The reasons for more difficulty is either the inclusion of servos, a dual supply, or extremely well matched input devices or higher quality IC's with very low offset.
Now WHY are capacitors a problem in the first place?
First a little history:
Back in the 1960's we made most audio products with a single power supply, with input and output capacitors, at a minimum. Usually we also had interstage capacitors, as well. To save space, we used tantalum caps that were polarized, and they almost always had some DC voltage across them, because of the single supply used, almost exclusively at that time. This was actually a small advantage that there was some DC bias on the polarized caps, but we did not necessarily know that at the time. It is one of the reasons that a tape recorder like the Revox A77 could sound pretty good, even by today's standards.
However, by 1970, we were trying to introduce dual supplies for both amps and preamps, and usually in the preamp case, in order to use IC's. This presented a problem with using the polarized caps, because they could be biased, either statically(DC) or dynamically in the wrong direction. What to do? We could not use Mylar or polystyrene caps, because they were just too large for the circuit space. Sometimes we used CERAMIC coupling caps, that were available in values up to 2 uf or so. Also, if we thought we could get away with it, we used tantalum caps in the feedback loop, and direct coupled the input and output. We felt that we had made the best 'compromise' possible, a single tantalum cap per stage (even though the cap had little or no DC voltage across it).
(more later)
In 1970'th the major direction in mainstream electronics (on both sides of the fence!) was to design topologies convenient for micro-miniaturization. That's why capacitors were considered as odd devices. As well as any other "external" components. Audiophiles tend to invent own explanations for everything they don't understand, so capacitors became "bad sounding" devices.
When I designed IC-based microwave alarm system I left 2 electrolytics only, outside of the IC, while the "prototype device" they gave me as an example of functionality, used 22 of them. I did that not because "capacitors are bad", but because of technology.
When I designed IC-based microwave alarm system I left 2 electrolytics only, outside of the IC, while the "prototype device" they gave me as an example of functionality, used 22 of them. I did that not because "capacitors are bad", but because of technology.
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Another comment on this topic of capacitors: When I was modifying the design of a power amp (a switcher, but that's actually not significant) I was able to eliminate the coupling capacitors in the signal path altogether, save the "indirect" effect of two caps associated with the d.c. servo. I tried my best to not require that the servo work too hard, but it had to accommodate variations in the input JFET stage as well as some presumed small offset voltage in the source.
Although one can hardly be objective when listening to one's own designs, I was pleased with the results. But I realized that another feature was a possible contributing factor: the input resistance was set rather high, to 1 megohm. This has the effect of making the presumptive output coupling caps in most sources have relatively smaller signal voltages across them, and their propensity for introducing audible artifacts correspondingly smaller. Of course the noise with an open input will be higher, but this is hardly relevant to actual applications.
Although these amps were designed for internal use in dedicated systems, two people wanted to test them before a trade show, and I wasn't there to see them hook them up. For some reason it didn't occur to them that using clip leads to attach the source to the amp was not a good idea, and they promptly smoked the output Zobel network as the amp broke into oscillation due to input-output coupling.
This drove a design change so that the amps would shut down when the Zobels sustained a lengthy overload. That little board got crowded by the end.
Although one can hardly be objective when listening to one's own designs, I was pleased with the results. But I realized that another feature was a possible contributing factor: the input resistance was set rather high, to 1 megohm. This has the effect of making the presumptive output coupling caps in most sources have relatively smaller signal voltages across them, and their propensity for introducing audible artifacts correspondingly smaller. Of course the noise with an open input will be higher, but this is hardly relevant to actual applications.
Although these amps were designed for internal use in dedicated systems, two people wanted to test them before a trade show, and I wasn't there to see them hook them up. For some reason it didn't occur to them that using clip leads to attach the source to the amp was not a good idea, and they promptly smoked the output Zobel network as the amp broke into oscillation due to input-output coupling.
This drove a design change so that the amps would shut down when the Zobels sustained a lengthy overload. That little board got crowded by the end.
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