I'm sure someone can help, I need to stop my tired old fridge from putting noise (via the mains) through my sound system. A new fridge isn't an option as yet and I'll happily modify the amp/preamp. Any practical solutions out there?
The best way is probably filtering the power before it gets to your equipment. There are power line filters available for this purpose.
Once AC noise gets inside the chassis of audio equipment, it can be very difficult to get rid of it.
If your house is old enough, make sure your stereo is not plugged into the same circuit as your ****. You can flip off the breaker or fuse to the **** and see if your stereo still works. If not find another plug that does.