sound quality difference between USB cables I am currently reading about Digital-Analog-Converters in a magazine. In one section about connecting an iPod, it says that the sound via a USB cable such as the one from Audioquests Cinnamon is significantly smoother and more velvety compared to the official USB cable from Apple.

Also, a standard USB cable: In the description of Audioquest "Coffee", they are claiming that there is a huge difference. And they cost about 280€! Or their "Diamond" version costs about 550€! Here is some review, again claiming that there is a difference. Here is another review. And here another one.

How can that be? The signals which go through the cable are digital. How can there be any difference?



(Just for reference, I also asked the same question on AVP.SE with similar answers.)
The digital path, as long as it is good enough to work, will not make any difference.

A long or poorly shielded USB cable can cause noise problems on the power supply side of the attached device. I have seen this on electronic test equipment using long and very thin USB cables. This has manifested itself as a 50Hz buzz on the 5V line which is then picked up by the ADC in the device. I would imagine it would be the same for any sound card.

Most cables are however fine.

The particular articles linked to sound like the usual made up audiophile rubbish though.