Another vote for a ground loop issue. I have had my (various) Dish receivers hooked to my stereo for years and have never had any issues you speak of.
I have also used the digital out on the back of my Dish receiver and ran it to my DAC. The sound was a touch better, but nothing spectacular; I was using it for the satellite radio stations and they are compressed.
I have also used the digital out on the back of my Dish receiver and ran it to my DAC. The sound was a touch better, but nothing spectacular; I was using it for the satellite radio stations and they are compressed.