Why is digital audio so complicated? Where did it all go wrong?

[Hifi_swlon]

I think that the process and handling of digital data is kind of more difficult than the inventors thought.….

What's curious though, is that digital data seems to work as the inventors intended in every other walk of life and under far more strenuous conditions.   The anomaly (audiophile audio) also happens to be the one where the effects are predominantly measured using devices that are uncalibrated and heavily interpreted by the brain  So, I suppose it's not hard to see why there are so many doubters….

I read all of the John Swenson articles posted earlier, (and some surrounding stuff) but also all the comments - and there are some notable objections to his theories.
The more I've read since the first posting, it seems to be pretty clear that no one today is saying any data gets lost or harmed - this simply can't happen without obvious dropouts as far as I understand - merely that other processes are maybe at play like possibly noise passing along the wire, and it being easier on the DAC to decode a more tightly clocked signal.  These 'problems' aren't inherent in digital audio data transmission per se, and if they have an adverse effect on the DAC should be  dealt with by the DAC itself - as long as the bits arrive safely at their destination it has complete freedom to deal with the data as it wants from its buffers. This doesn't appear to be the case right now though, but hopefully its not far off.

So I'm still not a naysayer, but I'm reaching my own conclusion that digital audio data is fine and works as intended, but that some DACs (or perhaps most DACs) allow themselves to be affected by extraneous noise or whatever coming down the cable.  I can live with that understanding (even though I still don't fully understand it), - at least it fits in with all current science and logic that I've been able to make myself aware of, and doesn't disagree with people hearing differences with front end changes.  I can't really see it justifying a USB cable at several hundred or even thousands of pounds though, but I probably never will

In my opinion there's a lot of unnecessary confusion about digital audio. It seems like things are actually quite simple, and I wonder whether once you've bought a bunch of expensive cables, galvanic isolators, re-clockers, regenerators, diamond tipped cones and whatever else can clean up this noise, you might as well have just gone and bought a new DAC that does it all for you!  Question is, does one exist?

Meanwhile, I foolishly pin all my hopes (at my budget) on the Sonore microrendu, which I hope will bring unprecedented levels realism to my system If not, get in line to try it out via the 'For Sale' pages

[Hifi_swlon]

f1eng, I actually think in some countries (even here?) for certain conditions acupuncture is accepted as legit?

I've found it really relaxing in the past anyway

[Antoine]

Great post Hifi_swlon, I actually fully agree with it. We really need our DAC's to take take care of the issues of which I am sure they're there now today in many products, including our Devialet's.

Although the source can mitigate some of the noise issues as well, I think it's the function and job of the DAC to be insensitive (to a very high degree) to outside influences. If it's all taken care of we'd of course not need to look for "band-aid add ons". I personally did not yet want to replace the Devialet and since it has a built in DAC I "needed" to resort to other measures, or better said through experimentation I actually found out it can be improved upon significantly.

By coincidence today I read about a relatively new TEAC DAC (http://www.teac.com/product/ud-503/) which already takes care of some of the issues mentioned e.g. USB/digital ground plane isolation. I believe it's not even very expensive. I'm sure, like I wrote before, it'll all soon be common engineering principles followed by all serious manufacturers. Don't forget that for example high speed USB (480Mbit/s) isolators didn't exist yet 6 months ago while there isn't a serious DAC without some form of isolation present in it's S/PDIF or AES3 inputs.

For now I personally think it's best to avoid using the USB, ethernet and WiFi inputs of our Devialets if one seeks the best SQ possible. If anyone wants to use USB I'd use a full galvanic isolator like the Intona or for computer audio the Mutec MC-3+ USB or perhaps the Berkeley Alpha USB, although this last one already is a bit dated.

Personally I will also not invest in any new Devialet hardware until they give their Expert product a serious technology update to address the issues spoken of here in this topic. Perhaps I'll even never buy a highly integrated solution like the Devialet again. In the future I may start using (at least) a stand-alone DAC because of the rapid technological advances being made here every day. For now though I am satisfied with the Devialet and the band-aids I've surrounded it with. If I can also scale down on the computer side of things and all the band-aids there, for example with the MicroRendu, I will not hesitate. Even though it all works perfectly today, the idea to have a clean and simple setup does sound attractive. A regular PC 'server' not near the system without all the linear PSU and USB enhancers, special software etc. feeding the Microrendu over the network and from there Mutec->Devialet would probably be ideal for me today. I would not want to go back in SQ though.

[f1eng]

f1eng, I actually think in some countries (even here?) for certain conditions acupuncture is accepted as legit?

I've found it really relaxing in the past anyway

It is indeed, but so are other placebos. In Germany it is legit for a doctor to prescribe sugar pills to a patient for ailments for which the placebo effect is known to be effective for those susceptible to it.

The placebo effect is real enough so being relaxed by acupuncture is an entirely plausible outcome.

[f1eng]

I suppose the magnitude of these differences are described differently by different people.
I still own the first (I believe) separate DAC available on the domestic market, a Sony DAS-702ES. I also have a Chord Hugo, a good modern DAC. I recently found the Sony in the cellar where it had been for about 15 years and compared the Hugo and old (>30 years) Sony. The difference was clear but much, much less than is commonly found between two phono cartridges, for example. I would not describe the difference as huge, but rather subtle, and that is the result of 30 years of development.
Mind you, I still have never tried the USB input on my Devialets so don't know how good or awful it can be, my main input nowadays is AES from CD transport with Air second and LPs next.

The only aspect of sound reproduction where domestic audio pushes technology is signal to noise ratio, other aspects are simpler than any other uses of digital technology I know of, and the digital side is less limiting in this aspect than the analogue part of the system.

[Antoine]

I suppose the magnitude of these differences are described differently by different people.

True, I also realize this and I'm sure most people will find no fault with using ethernet, WiFi or USB. Ethernet is actually very decent sounding although USB can sound even better with tweaks.

I myself (and of course others like me) am the "problem" here in my "perfectionists quest" to always try to improve on things. It's hard to go back though knowing things can be made significantly better than they already are. Also everone attaches a different value to these improvements. I'm sure quite a lot of us couldn't be bothered while I value these improvements very, very much.

[f1eng]

I suppose the magnitude of these differences are described differently by different people.

True, I also realize this and I'm sure most people will find no fault with using ethernet, WiFi or USB. Ethernet is actually very decent sounding although USB can sound even better with tweaks.

I myself (and of course others like me) am the "problem" here in my "perfectionists quest" to always try to improve on things. It's hard to go back though knowing things can be made significantly better than they already are. Also everone attaches a different value to these improvements. I'm sure quite a lot of us couldn't be bothered while I value these improvements very, very much.

Fair enough. I value improvements quite a bit too, I have never owned a hifi worth less than my car, for example, but if the choice arose I would still sooner listen to music I love on my portable than music which I am not fond of on my hifi.

[thumb5]

What's curious though...

Excellent post!  That's pretty much my thought process too.  Whether it's "the truth" or not is debatable but at least it's rational, justifiable and, equally to the point, a useful to guide how I spend time and money.

Just one extra comment, though: there seem to be a lot of generalisations bandied about (not particularly on this thread, I should say) about digital audio where what's true for (e.g.) AES/EBU is assumed to be true for USB, Ethernet, wi-fi, etc.  Presumably this is on the basis that "they're all digital", so they all suffer from the same pros and cons.  That way of thinking seems a bit lazy and doesn't make much sense to me, given that the protocols are quite different at many levels -- hardware and potentially software.

I admire Antoine's almost (dare I say?) fanatical devotion to the pursuit of the best possible sound quality from digital sources, even though some of the things he's doing might not be predicted by textbook theory to make any difference.  Since I don't think I'd ever have the patience or will power to go to those lengths myself, it's very interesting to hear about what works well and what doesn't.

[yabaVR]

...
The Nyquist–Shannon sampling theorem is not a theory, it is mathematically proved.

There are plenty of reasons why digital audio may not be to somebodies liking and there are plenty of ways in which it can be implemented imperfectly, but what you write is completely imagined gobbledygook. 

I am not religious either nor do I believe that homeopathy or acupuncture are anything other than placebos. Blind faith and belief in the implausible is not my thing, so excuse my being blunt.

Some of this is my opinion, some my experience of 50 years recording and some is straightforward mathematics (I concede that very few people have any mathematical aptitude though)

And don't think I have not listened, I am very sceptical and have always believed both that if theory and practice differ that the theory is incomplete and that if 2 things measure the same but sound different the wrong thing is being measured. I always check everything from first principles myself and have done many listening evaluations over the last 45 years.

Never said that the Nyquist-Shannon sampling theorem isn't right   . And in case you got me wrong, I don't own a turntable, I'm in the digital    .

So you mean there is no problem with time-inconsistency in the digital audio signal chain and the DAC putting the audio signal perfectly together every time? I didn't refer to anything else than time-inconsistency.
Why then does re-clocking, or a better external clock while recording, improve the digital sound? This is not blind faith and no placebo. We're not talking about digital measuring or pure digital information transport on computers/printers etc. That's a complete different thing (not time critical).

And for comparing a Chord Hugo to a Sony DAS-702ES and not hearing that much of a difference? You compared them to the difference of two phono-cartridges? That is apples and pears! One (digital) distinguishes in time-phase pattern, jitter etc., the other (analog) in distortion and frequencies etc. Totally different and not comparable.

I think we are talking on different level of listening and values.

It's a pitty we all live so far apart. I would much appreciate to sneak into Antoine's home and listen to his audio and I would say it could help you, f1eng, to new placebo-audio-horizons to accompany me  .

gui

[f1eng]

...
The Nyquist–Shannon sampling theorem is not a theory, it is mathematically proved.

There are plenty of reasons why digital audio may not be to somebodies liking and there are plenty of ways in which it can be implemented imperfectly, but what you write is completely imagined gobbledygook. 

I am not religious either nor do I believe that homeopathy or acupuncture are anything other than placebos. Blind faith and belief in the implausible is not my thing, so excuse my being blunt.

Some of this is my opinion, some my experience of 50 years recording and some is straightforward mathematics (I concede that very few people have any mathematical aptitude though)

And don't think I have not listened, I am very sceptical and have always believed both that if theory and practice differ that the theory is incomplete and that if 2 things measure the same but sound different the wrong thing is being measured. I always check everything from first principles myself and have done many listening evaluations over the last 45 years.

Never said that the Nyquist-Shannon sampling theorem isn't right   . And in case you got me wrong, I don't own a turntable, I'm in the digital    .

So you mean there is no problem with time-inconsistency in the digital audio signal chain and the DAC putting the audio signal perfectly together every time? I didn't refer to anything else than time-inconsistency.
Why then does re-clocking, or a better external clock while recording, improve the digital sound? This is not blind faith and no placebo. We're not talking about digital measuring or pure digital information transport on computers/printers etc. That's a complete different thing (not time critical).

And for comparing a Chord Hugo to a Sony DAS-702ES and not hearing that much of a difference? You compared them to the difference of two phono-cartridges? That is apples and pears! One (digital) distinguishes in time-phase pattern, jitter etc., the other (analog) in distortion and frequencies etc. Totally different and not comparable.

I think we are talking on different level of listening and values.

It's a pitty we all live so far apart. I would much appreciate to sneak into Antoine's home and listen to his audio and I would say it could help you, f1eng, to new placebo-audio-horizons to accompany me  .

gui

Maybe, but after 45 years as a hifi enthusiast I stopped messing around with stuff like this, which made imaginary (to me) differences, about 20 years ago and have enjoyed the music much more ever since
Digital is more time accurate than any analogue method, by the way, as well as lower distortion.

I have not experimented with USB yet, but I will, since there are intriguing possibilities.

Jitter was controlled to a small enough level to be inaudible on good DACs on SPDIF 20 years ago IMO, and even on cheap stuff now.