A different brand of sound card isn't going to solve your ground loop problems with your audio hook ups.

Is that always what these problems are? I have a similar setup at Empeg Towers, and suffered from loads of noise both from the car-player and from Winamp except during digital silence, and improved matters a lot by getting rid of junk I didn't need on the PCI bus and moving the sound card to the end slot, so there was nothing between its component side and the case.

Peter