That dreaded hum

Many thanks to all that have responded. The radioshack fix may be the best bang for the buck. Someone else had told me about the 75 to 300 ohm setup. I will try this first. Good listening.

I guess I should explain my setup: I have a hdtv box from my cable company--this connects to my tv via componet cables and audio cables. The cable signal of course comes from the wall. Next comes my dvd player(Philips 963sa)which also plays my cds and sacds. I have componet cables connecting to my tv as well as audio cables.(tv had multiple in & outs) The 963 also connects to my pre for cd listening. When I want to watch dvds I have to disconnect my coax from the wall to kill the hum. Funny thing is I don't get a hum with cable box hooked up the same as my dvd player. I know it sounds confusing but it's a quick fix I'm sure. Bob if I connect a ground as you explained it would have to connect to the cable box as it loops the tv via coax and componet cables. Mind you the only coax connection is from the wall to the box. I hope I made this a little more clear for everyone. I may just wind up with the Mondial box since it was made for my situation. Stay tuned.