Your buzzing sound looks like a ground loop in your system. If your interconnects are cheap they may be allowing some magnetic interference - and the transformers in your carver may not have been as active in this arena. If you're looking for a reasonably priced cable upgrade, Outlaw's own gets generally good marks in the forum.

If your residential wiring is the culprit, you may wish to buy a cheap circuit tester at home depot to check the proper ground on the outlet.

If your rig isn't using a power conditioner (ie, Panamax, TrippLite or Monster), that's a good way to solve this problem, albeit more expensive. Most of their units allow you to connect phone, network, and/or coax cabling to minimize this effect.