Hello. I've been using the SB Audigy External soundcard, and I wanted to just use my m-audio fast track as my primary soundcard. I plugged the RCA outs directly into my speaker setup and all the output sounds overdriven and fuzzy. I used to put my fast track into the Line In on my audigy and it was crystal clear. I don't want to resort to using my Audigy and I also don't want to buy studio monitors. I'm using 100 dollar Altec Lansing PC speakers already.

What is causing this grungy noise? Even the headphone output on the fast track has fuzzy noise

Thanks!