The Absolute Sound "review" of USB cable reads suspiciously like a press releaste

There is an excellent article from the late Charles Hansen Ayre designer about the USB DAC.  Although the article does not about USB cable specifically, but it will give you understanding of USB DAC architecture in general and how the cable "COULD" affect the sound.  I don't remember where it is but it used to be on Ayre website.  If I can find it I'll post it here.

For very high frequency applications like USB cables wouldn’t pure silver strands or silver plated copper strands be best, given that the signals travel very close to the surface of the conductors? Controlling the USB cables for directionality - as Audioquest does - also seems like a splendid idea. 🤗 I also like their “shield the shield” idea.

Actually for very high speed data, they don't really want it very fast.  If you look at those signal on the scope, the rise time looks more like a sine wave than a square wave.  High edge rate may cause a lot of EMI issues.

If you’re referring to the speed of the signal there is virtually no difference through copper or silver. In both cases it’s near lightspeed. 

If you’re referring to the speed of the signal there is virtually no difference through copper or silver. In both cases it’s near lightspeed.

I was referring to the data edge rate, not the speed in term of data rate or propagation speed.  The edge rate is the signal slew rate measured in V/sec.  You were referring to propagation speed which is measured by (radiant/meter). What I was saying is that fast edge rate might not be desirable.  If a cable made of silver, it will increase the edge rate which can potentially cause EMI issues and may end up having more jitter.  It's not a simple one rule fit all sort of thing, and silver may improve other aspect of the data transmission, but with respect to edge rate, it does not mean the faster the better.

With respect to USB asynchronous architecture, the jitter from the USB data stream is not an issue because the data is buffered before it is clocked to the DAC using a local clock that does not depends on the USB data stream.  It's how the USB data stream may cause jitter down stream to the DAC.  The faster the edge rate, the more like EMI will cause interference to ground, power and so on and ultimate jitter to the DAC. 

For synchronous USB, then may be silver could be better since it has faster edge rate and that could improve jitter.  That's why I am saying there is no one rule fit all but depends on other factors.

Isn’t slew rate a function of the amplifier? Not the conductor. The advantage of silver is that the resistance is lower. Maybe someone should come up with copper-plated silver wire. 😬