Try connecting one cable at a time and see which one buzzes. Sounds like a defective cable.
Buzzing IC's
Hi, I have an ARC LS25 mkII preamp and I've tried two different sets of the WBC Mogami 2549 shielded cables from Amazon. I'm using these between the preamp and my KEF KC62 subwoofer. They buzz when installed but when I throw on a pair of unshielded IC's no problems at all. Any idea what could be causing this? Thanks!