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

Showing 2 responses by emailists

emailists
923 posts
 
P05 sounds like you’re using the DIrectstream, as am I.

I recently did some listening tests with some albums that were released at 16 bits and then later at 24 bits (both at 44.1 and seemed like the same mastering)

The differences were very similar to looking at a jpeg with different color depths. The 24 bit had more tonal colors than the 16. Very easy to hear for an experienced ear- the average person may not have been able to tell, or possibly only after someone pointed out the increased and more natural sound.

BTW both files were converted to WAV.  A 16 bit WAV or aif might have been better than 24bit flac.  I was using jriver and a very powerful Mac with thunderbolt raid storage and EtherRegen. 
emailists
923 posts
 
Now that this thread has gone off the rails, I'd like add on my thought on spinning disks.  If the data was not fully retrieveable, would a DVD work?  Video signals I belive are more critical than audio signals in that we would see errors from the disk, possibly similar to the Compression, micro and macro blocking, banding and posterization seen on streaming video/cable tv.  
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