I have been having what appears to be the same hum as in this post

http://ubb.outlawaudio.com/ubb/ultimatebb.php?/ubb/get_topic/f/41/t/000156.html

I noticed this hum years ago but since the amp was in an open rack and I was using a RPTV I rarely noticed it.

Now I have a plasma tv and I have moved the amp into a more enclosed rack the sound is much more noticeable. I am certain it has something to do with power or filtering ( all of the components and tv are plugged into a monster power conditioner) as when I plugged my new tv directly into the wall socket the humming completely stopped. I am assuming I need to buy some other power conditioner. But which ones besides the one mentioned in the post above have people found will get rid of this hum?