Tried a few things now to cure what seems to be a ground loop in my system, which results in a hum/buzz at the speakers. The only thing that cures it is powering one mono block amp from another room (via extension cable, obviously impractical). Tried the following;
Powering all items from the same power line
Powering mono block amps directly from the wall sockets
(reluctantly) removing the shielding from one RCA out from the pre-amplifier
Wondering if anyone has used one of the following, or has any other suggestions?
(better half is getting annoyed by the trailing extension lead, I just wanted to put gaffer tape along it and pretend we were on stage, which went down well)