First post on the site, and figures it has to be about friggin' cables!
In my exprience, a slightly better than average cable (like the Belkin Gold) works well.
I had bought a MisterX HPDAC (2 of them actually, I usedone at work). Used a basic simple shielded USB cable, and with low impedence phones, I got horrible distortion. Brought e one at work home, it also had distortion.
Went back and forth with Marshall a couple times, then tried the Belkin Gold cord. No more distortion at all, with any phone.....
I haven't been able to tell any other difference, but there you have it. FYI, the old USB cable is connecting external HDD to my PC now, and never had any data errors FWIW.....
Now back to our regularly schedule snake oil discussion