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 14 responses by geoffkait

Stabilizing the disc is important, glad someone is doing that. But what’s that, 1% of the players? Hel-loo! Moreover, careful vibration isolation of the player from seismic type vibes is also important and separate from stabilizing the disc and requires an aftermarket solution. I’m not trying to set the world on fire, just start a flame 🔥 in a few hearts 💕
Everything is relative. As I oft say, audiophiles are prone to making declarations such as the ones you just made, I.e., that somehow modern players are superior by buffering, etc. While it may be true that some CD players are more innovative than others in dealing with these issues or other issues, all modern players don’t address the issues I mentioned, especially the scattered light issue.

I hate to judge too harshly but I don’t think any CD player manufacturer has even mentioned scattered light is a problem much less offers a solution. Self inflicted CD wobble and flutter is another issue very few manufacturers mention. The Green Pen is an example of a partial solution. Isolation is also a partial solution. Other older players stabilized the CD - e,g., Sony SACD PLAYER used a brass weight to hold the disc firmly, so that idea’s not new. It should be mentioned that a relatively inexpensive Tweak for an existing player must be weighed against great expensive of a “modern player,” assuming the modern player even addressed the problems, which it probably doesn’t.
No one is saying a DVD or CD won’t work. What I’m saying is the way the system was designed DVDs and CDs and Blu Ray appear to be working 100% but are actually working less than 100%. How much less less than 100% depends on many factors. Its not as if there are “data dropouts” that are audible or visible. It’s more subtle. It’s a subtle degradation of the sound or picture. It’s not the disc per se but how the disc is read. The disc has all the data, the system can’t read/interpret it accurately or completely. Think of it like an 8 cylinder car running on 7 cylinders. It will still run OK.
Perfect Sound Forever! The more things change the more they stay the same. 🙄
The best system I’ve heard - by far - is one for which the Reed Solomon error correction code subsection was disabled. Yes, I know what you’re thinking - is he out of mind? And once you stabilize the CD there is almost no need for the CD laser servo feedback system. Once you fix the underlying problems in the CD transport there is no need for all the patchwork fixes. The original designers obviously knew they had some problems with CD playback, they just didn’t know what all of the problems were or they ignored them. Do modern CD players just wish the scattered light problem away? I’ve never heard anyone even address the issue. If you could hear what I’ve heard with my ears.
So, modern CD players don’t use Reed Solomon codes or laser servo feedback? Reclocking and buffering takes care of everything?
“There are no uncorrectable errors.” That’s precisely what the industry said ever since day one. Hel-loo! “Perfect Sound Forever.” The Reed Solomon codes and the laser servo feedback mechanism were supposed to take care of any errors. What a joke. Buffering doesn’t stop all laser reading errors, by the way, only certain specific ones. If it did portable Walkman CD players would be perfect. Buffering only puts off the inevitable for a few seconds.
Streaming has its own issues, I don’t stream myself but that’s what I hear through the grapevine. 
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.

heaudio

On a serious note I doubt there would be many audiophile CD players in the last decade(s) that are not reading ahead if not retrying and buffering on digital output rendering jitter at the player level non existent and if you treat your CDs in any half decent fashion like I assume most audiophiles do, then uncorrectable errors are rare, and as per previous statement as the data is reclocked, any timing issues from pipeline processing of the error correction isn’t an issue.Enter your text …


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

Actually, no matter how good the DAC might be the damage to the audio signal still mostly occurs in the CD transport. The damage occurs as soon as the laser reads the data on the nanoscale data spiral. The damage is primarily caused by 1) the effect of external vibration on the suspended laser assembly, (2) the effect of thr CD fluttering during play (thus overdriving the laser servo system) and (3) scattered light infecting the data by getting into the photodetector. There are others reasons, too. Yes, I know what you’re thinking, “But I thought Reed Solomon was supposed to correct all that stuff.”

No matter how much you have in the end 🔚 you would have had even more if you started out with more in the beginning. 🔙 - Old audiophile axiom