For the longest time, I've had this annoying hum coming through my system ever since I switched to a stereo preamp and amp setup in my bedroom. Not just a quiet hum only audible when you put your ear up to the speaker, I'm talking about loud, overbearing, 60hz ground loop nastiness that was so bad I had to hook my preamp up to the variable inputs on my amp and turn the gain way down. Yes, THAT bad. I was sure it was the outlet, since my dad switched outlets in my room after we painted the walls, but the outlet tester read OK. Then I went to PS Audio's web page and found their "humbusters" tutorial. I quickly found out the source of hum was the cable tv connection in the room. Well, I couldn't unhook my cable every time I want to listen to music, and I didn't want to pay $50+ for an RF ground isolater/filter unit. After looking around at some web pages, I finally figured out what to do. Here's what I bought at Radio Shack today, for a mere $13: 1 2ft. length of 75 ohm coax cable 2 75 ohm - 300 ohm transformers 1 barrier strip I connected the 2 ft length of coax into the cable outlet in the wall into one of the transformers. Then I connected the back of the other transformer to the first one with the barrier strip, then connected the main coax cable into the last transformer. Cliff notes: What's happened is that my 75 ohm video signal is being converted to 300 ohms, then from 300 ohms back to 75 ohms between two isolated ground units inside the transformers. The hum is gone! My cable internet works fine, and I can't notice any degradation in video quality so far (I'm no videophile. but then again, it's just cable, so who cares if there's a slight difference anyway?). Just wanted to share that. I'm feeling damn victorious tonight.