USB signal timing goes mainstream. Just an FYI

The best USB DACs for music all use asynchronous mode.  Eliminates this as an issue.  I could go into detail.  But do your own homework.  EMM does, Wavelength Audio (Gordon Rankin) does.. as do many others.

You are correct both in the fact that they do, and that it ought to eliminate any difference.  And the EMM labs unit is excellent.  My prototypes also work that way*.  The fly in the ointment is.....ground and power noise still impact it and i do not fully understand exactly how/why. But they do.  And Ed has commented on this in the past too (i cant recall where).

At the very least though, a noisy ground and/or power supply, without isolation, can pollute the analog power supplies in any DAC. And those power supplies are, frankly, more important than most of the issues that audiophiles debate endlessly like specific chips....



* so far i have only in fact prototyped this part of the DAC - USB interface, powering, isolation, clocking --- and then spitting out either SP/DIF or if possible LRBW or I2S to existing commercial back-ends (DAC chip itself, reconstruction filter). These things take a lot of time to optimize.

i should clarify; i presume you mean DAC as master clock, with the ability to terminate, buffer, & re-clock, whcih is what i do and what i believe meitner does.

Any well designed DAC's USB  is asynchronous and uses its Clock. Retimers are different than reclocking and are useful for high speeds and long runs nothing home audio needs to be concerned about. Noise and jitter are not really a problem anymore as even well engineered DACs for a few hundred bucks these are well below human audibility.

Your basic argument is "you cant hear it". This is quite different from "it makes no difference" and the audibility is debated by many. Including me. I cannot explain it (and noted that above), i understand precisely what you are arguing, but neither you nor I, in fact, know what is audible. We have our opinions. Just sayin’.

The hearing range of humans isn’t opinion. If the DAC can produce a SINAD of -115db which even some $150 DACs can manage it would be interesting to know of someone who can hear distortion or noise of the DAC over that of the amp and speakers, that would truly be amazing. Just sayin’