2. digital
  3. 155131-20253

It isn't the bits, it's the hardware

I have been completely vindicated!

Well, at least there is an AES paper that leaves the door open to my observations. As some of you who follow me, and some of you follow me far too closely, I’ve said for a while that the performance of DAC’s over the last ~15 years has gotten remarkably better, specifically, Redbook or CD playback is a lot better than it was in the past, so much so that high resolution music and playback no longer makes the economic sense that it used to.

My belief about why high resolution music sounded better has now completely been altered. I used to believe we needed the data. Over the past couple of decades my thinking has radically and forever been altered. Now I believe WE don’t need the data, the DACs needed it. That is, the problem was not that we needed 30 kHz performance. The problem was always that the DAC chips themselves performed differently at different resolutions. Here is at least some proof supporting this possibility.

Stereophile published a link to a meta analysis of high resolution playback, and while they propose a number of issues and solutions, two things stood out to me, the section on hardware improvement, and the new filters (which is, in my mind, the same topic):



4.2
The question of whether hardware performance factors,possibly unidentified, as a function of sample rate selectively contribute to greater transparency at higher resolutions cannot be entirely eliminated.

Numerous advances of the last 15 years in the design of hardware and processing improve quality at all resolutions. A few, of many, examples: improvements to the modulators used in data conversion affecting timing jitter,bit depths (for headroom), dither availability, noise shaping and noise floors; improved asynchronous sample rate conversion (which involves separate clocks and conversion of rates that are not integer multiples); and improved digital interfaces and networks that isolate computer noise from sensitive DAC clocks, enabling better workstation monitoring as well as computer-based players. Converters currently list dynamic ranges up to∼122 dB (A/D) and 126–130 dB(D/A), which can benefit 24b signals.

Now if I hear "DAC X performs so much better with 192/24 signals!" I don't get excited. I think the DAC is flawed.
erik_squires
geoffkait's avatar
geoffkait
23,365 posts
 
Still, no matter how expensive it cannot address the self inflicted fluttering of the CD itself. As for the other problems I mentioned, it remains to be seen whether the Esoteric addresses any of them.
heaudio123
689 posts
 

>>>>>One assumes that is pure speculation or maybe wishful thinking.


Or, contrary to the post the reply was too, it was factual knowledge, and not an opinion or an unproven and evidence lacking hypothesis.
The CD can flop around like a beached whale in a tsunami, but unless there are unrecoverable errors, a buffered and reclocked modern audiophile player's output is not going to be effected.
This isn't the 80's and 90's when due to cost and limited functionality of player mechanisms you were beholden to the recovery of data impacting the clock PLL, and jitter due to the variable error recovery pipeline.
erik_squires OP
16,395 posts
 
I should point out that in the experiments I was able to do, with 2 different DACs of different ages, I exclusively used a streamer. No CD Fluttering was there.

Best,

E
geoffkait's avatar
geoffkait
23,365 posts
 
Streaming has its own issues, I don’t stream myself but that’s what I hear through the grapevine. 
erik_squires OP
16,395 posts
 
I realize now I did not include my own experiences for brevity.

I had the chance to own simultaneously an ARC DAC 8, along with a Mytek Brooklyn. I streamed to both of them.

I also used a Wyred4Sound Remedy asynchronous sample rate converter).

To make a long story short, and leave myself open to uninformed nit-picking, I’ll say the following:

The gap in playback quality between Redbook and 96/24 was wide in the ARC 8. It was very very narrow in the Brooklyn. In all cases, the Brooklyn was superior. The ARC 8 benefited from the ASR a great deal. The Brooklyn did not.

Given that the Mytek was better in all ways AND also had such a slim difference in performance I concluded that maybe the problem was not the data, as we have so often thought, but how well the DACs behaved with Redbook. I've had similar experiences with a number of modern DACs. Some very inexpensive. The playback gap has all but vanished over the last 15 years. What was once obvious is now gone.

Yet, despite this, I have seen many times people take my experience as evidence of data missing in Redbook. No matter what evidence is presented to the contrary.

Anyone who relies on upsampling in my mind is also taking advantage of a DAC simply performing better with high resolution data, even though upsampling CANNOT under any circumstances add information that was not there before. If upsampling works, at all, then it means the DAC does not perform equally at all resolutions. It has nothing to do with missing data.
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