New electrical wiring specifications

@skyy92677  

At the suggestion from another user I bought the little red Amazon plug in circuit tester. It’s showing me I have 7 milliamps going  to ground, Google says this is quite bad. I turned off the all the breakers and that didn’t change anything it’s still 7ma. It’s so bad that when I turn the whole house surge on you can hear the toaster buzz!

That might have been me, but you are misreading that 7mA!! That’s the GFCI test level.  That is, if you are testing a GFCI protected outlet, and you press the TEST button you can expect 7mA to flow.  That’s very little, but any more and you can stop a heart. 

The important part of that test is to look at the AC and the N-E voltage.

Having said this, if you have  this hum occuring no matter where the gear is you may have DC.  If it’s happening only in the listening room the advice to disconnect any other copper wires like coax and Ethernet is valid.  

Personally at the distance you almost should consider a new 60 Amp subpanel in your listening room and very short runs to the receptacles.  I haven’t done the math in a while but I did ages ago for a workshop.  The 4 gauge wiring required for the 60A subpanel will outperform 10 gauge at higher loads, plus this way your ground and neutrals join together much more closely and are unable to develop a higher potential like you could with long, separate runs.