How do I get rid of a hum when my dvd and tv are connected?

Q: I'm trying to get DVD audio into a mixing board(radio board) cleanly. The DVD audio is clean UNTIL I connect it the video cable between the TV and DVD player, then a strong hum comes through. I tried different tvs and dvd players, and the hum always returns once the video connection is made between the tv and dvd player. I've also experimented with grounded power strips and shielded cables with no success. I'm trying to get DVD audio for audio production, so the hum negates using the 'hum-backed' audio.

A: The problem you are experiencing can be really really difficult to solve. I have spent hours and hours chasing hums in distributed AV systems. The quick answer is that there is a ground loop issue. This site has a couple of ideas

http://www.channld.com/hum.html

You can often get rid of by plugging all of the components into the same outlet, which remove ground difference since they share the same ground. Cutting the grounding pin off of your component is not usually a good idea, as it leaves your component ungrounded. If you have cable (as in TV signal) running into any of the components, there is often enough DC current in the cable signal to cause a ground hum. You can buy a cable ground lift from Radio Shack. I hope this helps...