If it's your cable coax line tr this I do t all the time ang get great results. Re-terminated your coax line but this time add a 18ga. drain wire to the shield/ground termination. Attach drain wire to cold water pipe and your done. You'll notice the hum disappear, picture quality improve as well as your stereo sound if placed close to cable box. If grounding the coax directly scares you, just attach a ground wire to the cable box metal chassis and then the cold water pipe. This does the same thing. Good luck.
Grounding problems-- Help!
I just bought a McCormack DNA 1. I am using the creek OBH-12 passive device as a preamp and my source is a Rega Planet. My speakers are ML areius i's. I hooked it all up and I'm getting a nice hum at 60hz. Please give me tips/ suggestion. I don't know anything about grounding problems!