If you feel the mains is the source of your noise, you may want to try a good mains filter.
I use pure silver cables (no copper) all the way through and do not exhibit the noise you speak of. That said every component goes through a mains filter AND an isolation transformer. Each component has it's own isolation transformer.
My cables (IC and speaker) are also active - they have a 9v positive bias on the shield that is shunted to ground.
I use pure silver cables (no copper) all the way through and do not exhibit the noise you speak of. That said every component goes through a mains filter AND an isolation transformer. Each component has it's own isolation transformer.
My cables (IC and speaker) are also active - they have a 9v positive bias on the shield that is shunted to ground.