If you are using this with a USB input, do you need a soundcard in your computer?????
Here's the Crutchfield info on the mysterious USB input:
USB Input: By connecting the USB port on your computer to the USB input on the back of this unit, you can listen to music (and any other sound) from your computer with excellent quality. The following system requirements must be met to use the USB input with PCs and Macintosh computers:
System requirements for PC compatibility:
Windows compatible PC with a Rev. 1.0 compatible USB port
Windows 98, 98SE, Me, 2000 or later operating system that supports USB
System requirements for Macintosh compatibility:
iMac, iBook, or Power Macintosh or PowerBook with a built-in USB port
Mac OS 9.0 or later Mac OS that supports USB
USB Mix Level: When using the USB input, you can also listen to another source (CD for example) and the relative volume of the USB input can be adjusted with the USB mix level knob.