Can somebody even try to explain to my simple brain, why many non-digital filtering DACs sound so good even though probably account the most for one of the theoretically most easily audible artifacts in DAC performance: intermodulation distortion.
A DAC that does not do any filtering beyond 20 kHz will help ultrasonic frequencies to form (when used with most speakers) intermodulation components in the audible range.
This, as I understand, should sound very nasty, considering how sensitive human hearing is to intermodulation distortion (in general, of course there is masking).
I'm not trying to put down any approach or to claim somethign silly like, filterless DACs can't work.
I'm just interested, whether anybody has a working theory on why we hear what we hear, although measurements and theory might suggest otherwise.
Also, please note that I'm trying to confine my question only to intermodulation distortion in speakers in regard to DAC operation at high frequencies.
Comments?
regards,
Halcyon
PS I've used the search, but couldn't find specific issues relating to this. If I didn't search properly, I do appreciate links as well. Thanks.
A DAC that does not do any filtering beyond 20 kHz will help ultrasonic frequencies to form (when used with most speakers) intermodulation components in the audible range.
This, as I understand, should sound very nasty, considering how sensitive human hearing is to intermodulation distortion (in general, of course there is masking).
I'm not trying to put down any approach or to claim somethign silly like, filterless DACs can't work.
I'm just interested, whether anybody has a working theory on why we hear what we hear, although measurements and theory might suggest otherwise.
Also, please note that I'm trying to confine my question only to intermodulation distortion in speakers in regard to DAC operation at high frequencies.
Comments?
regards,
Halcyon
PS I've used the search, but couldn't find specific issues relating to this. If I didn't search properly, I do appreciate links as well. Thanks.
NON-OS DAC's
Hi halcyon,
In my experience a digital filterless DAC sounds better with analog low-pass filtering applied. Probably due to the intermodulation effect you described. The <B><I>technical</B> </I>problem is how to filter and pass the audioband as much unharmed as possible. I also did not like the sharp staircase signal on top of a 3150 sine signal. I wanted it smoooth. Despite NON-OS concept DAC's do sound very different from each other. I have tried AD1851N-J, AD1864-J, AD1865N-J, AD1865N-K , TDA1541AS1, TDA1543, TDA1545, all NON-OS. And the winner is.....?
Hi halcyon,
In my experience a digital filterless DAC sounds better with analog low-pass filtering applied. Probably due to the intermodulation effect you described. The <B><I>technical</B> </I>problem is how to filter and pass the audioband as much unharmed as possible. I also did not like the sharp staircase signal on top of a 3150 sine signal. I wanted it smoooth. Despite NON-OS concept DAC's do sound very different from each other. I have tried AD1851N-J, AD1864-J, AD1865N-J, AD1865N-K , TDA1541AS1, TDA1543, TDA1545, all NON-OS. And the winner is.....?
Halcyon,
I think that whatever theory comes up the practical result is what counts isn't it ? The explanation you want is the explanation the builders of non os DAC's want to learn too.
To my simple brain the lower sensitivity to jitter counts for a great deal in the results
Please see this interview what Kusonoki has to say about digital filters: http://www.tnt-audio.com/intervis/kusunoki_e.html
I think that whatever theory comes up the practical result is what counts isn't it ? The explanation you want is the explanation the builders of non os DAC's want to learn too.
To my simple brain the lower sensitivity to jitter counts for a great deal in the results
Please see this interview what Kusonoki has to say about digital filters: http://www.tnt-audio.com/intervis/kusunoki_e.html
tiroth said:
What makes you say this?
Have you actually tested various filters and their audible effects on AID with loudspeakers?
That is, not just looking at thing in an oscilloscope?
Mr Black (the author of AID article) seems to have done his homework and even his old ears can hear the intermpodulation components.
Why do you think that moon phase, cabling and other issues you mention are somehow comparable in audibility?
Have you actually listened experimentally for the differences in moon phases to audio quality?
I wish that people were not so eager to ridicule other people's sincere work, unless they have some experimental results that absolutely prove the opposite and that they think that the situation calls for humor.
Sarcasm is the most shallow of the intellectual traps, IMHO.
regards,
Halcyon
PS I think A LOT of the stuff on this forum is A) self-righteous mockery by people who have not tried it themselves, B) pseudo-theoretical "can't be true, because text book say so" arguments. I'm guilty of this myself often. I hope you are not
Dear halcyon
Please visit
http://www.jensen-transformers.com/apps_wp.html
and ask for AES Preprint
Spectral Contamination Measurement
by Deane Jensen/Gary Sokolich
Then you will realize the stupidity of filterless DACs
Regards
Please visit
http://www.jensen-transformers.com/apps_wp.html
and ask for AES Preprint
Spectral Contamination Measurement
by Deane Jensen/Gary Sokolich
Then you will realize the stupidity of filterless DACs
Regards
That's right for sure.
I think it is possible to separate the A en B types from serious posters. Like ... myself
Joke, don't take this serious.I tried this non os thing and I am continuing to do so although the textbook says it can't be good to my ears. The reason for the good results I can't find. Honestly I gave up finding one...
I read a lot about the subject and there simply isn't a consensus about the difference between theory and practice.
Why do we always have to read this kind of crap ? If it is driven by stupidity why are the results good then ? Everybody that hears the DAC's likes the sound so far. My speakers like them.
I like them. Stupidity is calling others stupid because they don't think the same as you do.
Please be assured that I was not ridiculing anyone. Although my tone was sarcastic, I was quite serious with my comment. When we discuss images which can extend to the low megahertz range, stray capacitance of cables and interconnects, amp topology, layout, EMI susceptibility and a host of other factors can mitigate or enhance potential IMD effects. Thus a filterless DAC may sound very different even with the same source and amp, depending on the setup used. (and phase of the moon)halcyon said:
dimitri said:
Thank you, I will. However I already know various theoretical points why other people tend to think that they such DACs are crap due to how they operate on the signal.
But can you explain why it SOUNDS so good?
Please understand that map is not the same as terrain. One is a facsimile of the other.
Anybody can keep on quoting text book claims, but can we synthesize a testable hypothesis as to why the sound is so good to human ears?
Is this a 'mere' psychoacoustic phenomenon or are fundamental signal integrity issues also at play here?
regards,
Halcyon
PS Tiroth, now I understand your point. Thank you for the clarification.
Halcyon, you're alone in the desert. I am keen on following this thread but nobody seems to be able to synthesize a testable hypothesis as you call it.
Maybe this is due to the fact that most of the visitors are DIY ers ? That build the thing without having to understand WHY sound is good ?
Will there be any "real" audio engineers out there that symphatise with the non os topology at all and have a suitable theory/practice evaluation ?
Don't throw the towel in the ring.
Regards,
Jean-Paul
PS the comparison with the Mac community comes to mind.
Maybe this is due to the fact that most of the visitors are DIY ers ? That build the thing without having to understand WHY sound is good ?
Will there be any "real" audio engineers out there that symphatise with the non os topology at all and have a suitable theory/practice evaluation ?
Don't throw the towel in the ring.
Regards,
Jean-Paul
PS the comparison with the Mac community comes to mind.
I would like to make a clarification that some of you may agree with and some may not. If all of you agree with me, then I would probably be on the wrong site.
While we are comparing OS with NON-OS DACS, I think what we are really comparing is NON-OS DACS with OS DACS based on linear phase digital filtering. Yes, there is a difference. I am not saying which is better, just that they are different. It is possible, to build an OS-DAC using linear phase filtering that would have all the benefits of the NON-OS DAC in terms of transient response, but pushes the aliasing artifacts up in frequency to allow easier analog filtering. By possible, I mean mathematically perfect. We are still in an analog world, so things such as clock jitter, etc. will still be an issue.
While we are comparing OS with NON-OS DACS, I think what we are really comparing is NON-OS DACS with OS DACS based on linear phase digital filtering. Yes, there is a difference. I am not saying which is better, just that they are different. It is possible, to build an OS-DAC using linear phase filtering that would have all the benefits of the NON-OS DAC in terms of transient response, but pushes the aliasing artifacts up in frequency to allow easier analog filtering. By possible, I mean mathematically perfect. We are still in an analog world, so things such as clock jitter, etc. will still be an issue.
----
Why do we always have to read this kind of crap? If it is driven by stupidity why are the results good then? Everybody that hears the DAC's likes the sound so far. My speakers like them.
I like them. Stupidity is calling others stupid because they don't think the same as you do.
----
Have you ever try to apply ultrasound signal to the ordinary amplifier? Have you seen on your scope/analyzer the results? Have you thrown dozens of output devices/tweeters to the trashcan because of a very small hf content at the input? I do.
----
But can you explain why it SOUNDS so good?
----
They don’t sound good, they sound DIFFERENT. Now I have AD1851 NOS DAC, but with output filters. The freeware soft FilterLab v1.0.40 for the filters you can find on www.microchip.com/download/tools/analog/flab/flb1040.zip. There is anti-aliasing filter wizard also.
I also have TDA1543 NOS DAC with R I-V conversion. Several days I enjoyed how it sounds, and then I feel the fatigue. Now I switch it on maybe on 5% of my CDs. Yes, on these 5% it sounds better, but I don’t know how these CDs were recorded.
----
Is this a 'mere' psychoacoustics phenomenon or are fundamental signal integrity issues also at play here?
----
I think that is real psychoacoustics phenomenon, which was discussed in JAES in early 90th – the audibility of anti-aliasing filter (configuration, response, etc)
----
Maybe this is due to the fact that most of the visitors are DIYers? That build the thing without having to understand WHY sound is good?
----
This is right. It is psychological issue, nobody will criticize it’s own offspring. Could you say, that you’d spend hundreds of hours of your invaluable time to build this DAC, and that in the long run the sound is not satisfying? It is impossible to spend $50 and make a good DAC, please don’t refer to the 47 lab, that’s frauds, it is marketing issue how to sell $50 DAC to you for $1000 …
Why do we always have to read this kind of crap? If it is driven by stupidity why are the results good then? Everybody that hears the DAC's likes the sound so far. My speakers like them.
I like them. Stupidity is calling others stupid because they don't think the same as you do.
----
Have you ever try to apply ultrasound signal to the ordinary amplifier? Have you seen on your scope/analyzer the results? Have you thrown dozens of output devices/tweeters to the trashcan because of a very small hf content at the input? I do.
----
But can you explain why it SOUNDS so good?
----
They don’t sound good, they sound DIFFERENT. Now I have AD1851 NOS DAC, but with output filters. The freeware soft FilterLab v1.0.40 for the filters you can find on www.microchip.com/download/tools/analog/flab/flb1040.zip. There is anti-aliasing filter wizard also.
I also have TDA1543 NOS DAC with R I-V conversion. Several days I enjoyed how it sounds, and then I feel the fatigue. Now I switch it on maybe on 5% of my CDs. Yes, on these 5% it sounds better, but I don’t know how these CDs were recorded.
----
Is this a 'mere' psychoacoustics phenomenon or are fundamental signal integrity issues also at play here?
----
I think that is real psychoacoustics phenomenon, which was discussed in JAES in early 90th – the audibility of anti-aliasing filter (configuration, response, etc)
----
Maybe this is due to the fact that most of the visitors are DIYers? That build the thing without having to understand WHY sound is good?
----
This is right. It is psychological issue, nobody will criticize it’s own offspring. Could you say, that you’d spend hundreds of hours of your invaluable time to build this DAC, and that in the long run the sound is not satisfying? It is impossible to spend $50 and make a good DAC, please don’t refer to the 47 lab, that’s frauds, it is marketing issue how to sell $50 DAC to you for $1000 …
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