Will a quality USB cable make a difference....

"I agree with you about timing variations. There's also latency, packet loss/corruption, and a host of other issues that can affect USB (or any almost any other data connectivity protocol)"

No, I think you missed the point. Its the cycle-to-cycle timing variations, the jitter that sets audio streaming apart from other applications of USB. This is not about missed packets or data errors. These are extremely rare.

"Anyone who wants to can find and read Gordon Rankin's excellent white papers on USB and specifically asynchronous mode operation."

Gordon does understand a lot about the software and protocol aspects of USB. That is his strength IMO.

I, on the other hand have strengths in high-speed digital design, transmission-line effects and other relevant design areas. Gordon is not the only one with async USB interface designs.

I have found that none of these async USB interfaces are completely immune to the benefits of a good USB cable, not Gordons, not mine. I have not discovered the exact mechanisms, but I know its true.

Steve N.
Empirical Audio

"Gordon is not the only one with async USB interface designs."

I'm pretty certain he was the first though!

"I'm pretty certain he was the first though!"

I believe Ploytec and other Pro Audio designers had async designs out first, resulting in products from EMU and Tascam. I interfaced these to my Pace-Car.

Steve N.
Empirical Audio

Steve,

Streaming data is streaming data, whether it's audio files or instrumentation data. It's either bit perfect and time correct or it's not. Yes, jitter is problematic but, as I'm sure that you would agree, not nearly as much with USB2 as it was with USB1. I'm sure that my next comment will further endear me to the peanut gallery, but frankly, I will say that I believe that most audiophiles can't discerne jitter (w/ USB2), and wouldn't know what it sounded like even if if they could. What's the worst jitter you have measured for USB2 gear that was in spec? Probably not more than 125uS or so, and I don't know anyone who can detect that. I believe that most of the sound effects that are erroneously identified as jitter are in fact the result of elasticity buffer stack overflows.

Re: my comment for Gordon Rankin - I was not making a wholesale endorsement of Gordon or his products. I have never met the man, but I'm sure that he (like you) is a smart guy. I was simply recommending his whitepapers to another poster as a good primer on USB, since there seems to so much misinformation bandied about on this forum.

Ed,

Dude, did I run over your cat or something? I apologize if I inadvertently besmirched one of your audio idols. But I would appreciate it if you would stop lecturing. As I have said previously, you don't know me or anything about me. Your assumptions and guesswork are both incorrect. If you want to know something about me, just ask. I am an open book.