I have hooked up my computer to my a/v receiver and I get an annoying hum coming from the receiver/speakers. I've connected my Creative Audigy2 soundcard line-1 out port with a 1/8" stereo phone jack to an RCA cable, then a Y-splitter, to my Onkyo TX-DS595 tape ports. I get the hum even if I'm listening to another source (other than the PC/tape). Setting the PC audio out volume to any setting doesn't help. Any ideas?