Speaker Hum

@jdm11

unplug the HDMI cable to your tv from cable box.

As articdeth suggested, this would be easier than disconnecting the coax cable from the modem or cable box, but if that doesn’t do anything, at some point I would try disconnecting the coax cable to the cable box or modem.

Also when I moved in I had every outlet in the house with new GFIs - would the electrician have noticed if the box / grounding in the house was off or not necessarily?

Most GFCI’s will not work correctly without a ground. Yes, they make ones that work in situations where a ground doesn’t exist, but if you had any of those, he would have had to install specific GFCI’s for that application. If this were the case, I think he would have mentioned this to you. Hard to say if he would have pointed out any other electrical abnormalities. Some houses that were built in the 60’s contained aluminum wiring instead of commonly used copper. Do you remember him mentioning anything about this to you? Not every house in the 60’s was built with aluminum, but it was more popular during that decade than any other.

Maybe I need to disconnect them all from the amp as well or that doesn’t make any sense?

YES! Definitely try that! If THAT fixes the problem, try plugging them back in one source at a time, and see when the hum starts again.

Are your outlets really grounded?  My house was built in 1962 and most of mine are not. A previous owner replaced outlets with GHI outlets for some reason and they’re NOT grounded! I had to run a new circuit to my listening room.

BTW, have you tried a cheater adapter? That has helped me more than once.

Certainly one of the more frustrating situations....In my case, after a lot of trial and error, my problem went away after I realized it was the wifi router. Moved it further away and problem disappeared for good.

If you listen with headphones  is the hum still there?

(I had an integrated amp that had a voltage leak from one of the components in the power amp section... headphones sounded great but speakers had a 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.