whom do i get to fix a ground loop hum?


is it the cable guy(i heard) or do i need an electrician? thanks, d. p.s. i am using cheater plugs now but they only diminish the hum. thanks!
uncertainsmile
In my case, I have 3 dedicated outlets for audio only and I was still getting hum when I plugged mono amps to each outlet and preamp/CDP to third outlet.
By simply plugging preamp/CDP to the same outlet as one of amp, hum got reduced significantly.
Also Device called Groun Zero from Granite Audio is available.
But do not know how it needs to be installed ir works.