Ground-Loop Isolator... (Score 1)

There are ~$10 RCA to RCA audio ground-loop isolators available from the er... crack shack ;-)

Seriously... they work wonders (all my components are isolated this way, long story :). They're basically audio-isolation transformers in the middle of an RCA patch cable.

These will kill 90%+ of the 60/50Hz hum present in audio equiment "chains" of devices... (ex: LaserDisc player to VCR to TV...).
-Phyxis