I am still looking for *any* evidence that a digital cable affects sound. And by "any evidence" I mean either:
1. An explanation that my poor brain can understand.
2. A trial that my poor ears can listen any difference.
So far, alas, I have not found any. If people have (1), please share. As of (2), I'll keep looking in head-fi meetings. And, of course, I'll receive a 1G cable when my pulse eventually arrives. I'll try an A/B against a cheap USB cable.
The only 'expensive' USB cables I have ever tried, costing only in the range of $75, and I couldn't hear any difference with sub $10 cables (using pretty good gears, HD800, T1, etc). But I'm open and really eager to find the truth or to hear any difference between sub $10 good quality USB and those > $100 USB cables. I know SPDIF coaxial cable might have problem with reflection, thus there might be differences between cables. But for USB, I don't see any good explanation so far. Probably good conductor for the power section might cause a different, but that would apply only for DACs requiring power from USB port.