You more than likely have a ground loop. I also had this problem. The only way I was able to get rid of it was to have an electrician run a ground cable from the satelite grounging block to the house ground in the breaker box. You can probably do this yourself. I had an electrician do it when I had a dedicated line put in for my system. Mondial makes a magic box device that works for cable but it will not work with the digital signal from your DirecTV dish. There is at least one other thread here on Audiogon about this issue that I remember reading within the last few months.
Direct TV causing hum in audio system
Hello,
I'm experiencing a humming problem when I integrate my direct tv into my audio system. When I disconnect the satelite cable, the hum goes away. Am I experiencing a ground loop? Is the solution to ground the satelite dish? (I had the dish installed free as part of a promotion.) I heard cable tv can cause this problem and wondered if satelite tv is any different?
I'm experiencing a humming problem when I integrate my direct tv into my audio system. When I disconnect the satelite cable, the hum goes away. Am I experiencing a ground loop? Is the solution to ground the satelite dish? (I had the dish installed free as part of a promotion.) I heard cable tv can cause this problem and wondered if satelite tv is any different?