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



Will a higher quality USB cable make a difference when being used between a storage device (bus-powered mobile drive) and a music server (w/o DAC), as opposed to those used between a source (iMac) and USB converter/DAC? Can anyone confirm an audible improvement?
sakahara
Steve, I didn't read your post until after my little rant. Please keep in mind that USB is not an audio interface - it's a source to peripheral device connectivity bus. As far as USB is concerned, there is no difference between audio files and jpeg photos, an Oracle spreadsheet or java code. The "audio interface" part starts on the outbound side of the DAC.

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). But I was responding to a poster that claimed that changing USB cables provided " The top end air, the transparently and better defined bass are easily distinguished differences." That's not a phenomena that can be attributed to error correction, or timing, or latency, or voltage regulation, or phase lock, or... whatever.

It's easy to say ignore or dismiss the science involved in audio. Over the course of human history, anything we can't explain (or didn't want to take the time to understand) is described as magic. Well, guess what? There is no magic in audio, just a lot of science. Circuit design is a science. Tube design is/was science. Acoustic speaker and cable design is science. Transformers, resistors, capacitors - all based on good, hard scientific principles.

About two years ago we had a job for a major aerospace company, designing a system to collect and sample broad spectrum analog audio feeds some remote sources. Very remote. Anyway, when we used USB 2.0 for part the low-res portion of the system, and in our testing we found that for cable runs of up to 20'-25', the actual cable (manufacturer, country of origin, jacket, etc.) made no difference. The connectors use for the USB cables made a measurable difference in the amount of packet error correction that was required. Upgrading the USB connectors on the source systems and target devices made a huge difference, dropping the packet error rate down to almost zero; even if used with the least expensive commercial cables.

My last word on this incendiary topic: all this information is available online. Anyone who wants to can find and read Gordon Rankin's excellent white papers on USB and specifically asynchronous mode operation. They provide an excellent explanation on how USB works, so nobody has to guess.
Br3098...personally I think it's hilarious that you would lecture Steve Nugent in your post... especially suggesting that Steve is one of those who >>...has to guess<<.

My suggestion to anyone reading these posts is to pay your own tuition (it's very modest compared to Koegz's suggestion of >>putting their [your] money in the best equipment they [you] can afford in the body of their [your] system! Body= speakers, amp, line stage and dac.<<): try several modestly priced, reputable USB cables... get them previously owned and used on Audiogon for a fraction of their original cost... and decide what works for you.

Listen with your ears, not your eyes and reading, and you will find what satisfies you.

The bottom line is that some of the above posters are suggesting that you can use just about any industrial USB cable out there... ones used for printers and any other utilitarian purpose... and you will receive the same musical qualities that a more expensive audio USB cable will provide. That might turn out to be the case, but it's not my experience and not the experience of many other DAC-based music lovers.

I agree with Steve Nugent; some of the arguments made in this thread are >>tired<< and I might add, tiring.

My only concern in this is the misleading (and disinformation) of those new to computer-based audio, specifically USB DACs. There's many promises made out there by DAC designers and manufacturers, and there are many adequate, good, very good, and outstanding designs. Newbies will not realize the full potential of the DAC of their choice without careful experimentation to find the cabling, particularly USB cabling, that will maximize the musicality of their chosen DAC source.

:) listening,

Ed
"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!