Speaker Hum

Sorry @dpop but all GFCI outlets will work without a ground. It is surge protectors that need.a ground.

Gfci outlets compare the current on the hot and neutrl and trip when they are not equal. Ground not required, but you are required to stick the little "no ground" stickers on.

@erik_squires 

all GFCI outlets will work without a ground

You are correct. I never knew that before. Thanks for pointing that out! The situation could be very deceiving for some (especially audio-enthusiasts plugging their audio equipment into GFCI's that they think incorporate a true earth ground), since the GFCI will trip when needed, even though a true earth ground may not be present on the particular GFCI.  

@dpop That’s why you are sopposed to add the little labels which no one does and no one reads. 😁

GFCI’s are the only approved way of adding a ground pin outlet where a ground wire does not exist.

Really, any audiophile moving into a home needs to do a thorough inspection. My home was only 15 years old when I moved in and I eventually replaced 100% of the light switches and about 70% of the outlets (so far). All the crap I found. Corroded outlets, loose wires, intermittent switches, wrong outlet types or wrong covers, stuff stuck in outlets, scorch marked outlets and wire terminals.

I’m not going to advocate for cryogenically treated hospital grade outlets, but damn, I sleep a lot better at night by going through the basics thoroughly and getting rid of all the back-stabbed connections. 

After reading through the thread I am unsure if you tried this. After 20 years in the same house my speakers developed a hum one day this year. I tried unplugging everything one at a time including the cable box to no avail. Still had a hum. At the suggestion of the amplifier manufacturer I disconnected the COAX from the wall to the cable box. No hum. Installed a COAX inline isolation transformer and no hum (or maybe 99% less hum). I was misled thinking unplugging the cable box was the same as disconnecting the cable box COAX in. FWIW.

Jim S.

@erik_squires

any audiophile moving into a home needs to do a thorough inspection.

Totally agree, and I too also recommend and encourage it be done. In addition to running some new circuits, I replaced all switches and outlets in my home when I moved in 21 years ago. Yeah, I too hate the back stabbed method of connecting outlets or switches. None currently exist in my home, and when doing maintenance work anywhere else, I never ever use that method of connection.

If you look at my virtual system pictures, you’ll see the meter I use to measure my home ground system resistance (which measures under 1 ohm). It’s a meter I also use in the radio broadcast industry to measure ground resistances in broadcast facilities.