I recently (finally) got a laptop and started getting it set up for music (cdg and karaoke later...), and when I hooked it up to the amp, got the worst hum I have heard in a long time.
After isolating the trouble to prove it was only happening with the laptop power converter plugged in, I came back here and low and behold, the search function worked great and I found the exact cure. Found an old reply from lyquiddye giving a Rat Shack link
http://www.radioshack.com/product/index ... age=search It came with its own 1/8 inch adapter to plug into the laptop, all I had to add was a couple of RCA to 1/4 adapters to plug into the amp.
I just wanted to say thanks, and bring it up again in case someone else has the problem. I went online, checked online at the nearest store, went and bought it, and was back in business with good clean sound in just minutes..... kewl!
Sharing problems, and more importantly the fixes, is great!