i was checking them out on ebay. it claims to output "virtual 5.1 suround sound" via the usb port. does anyone have any experience with these items. is it worth it? can i put a center channel running off this?
I recommend the turtle beach audio advantage micro usb sound card. It's about fifty bucks, and sounds stellar.
It has a dual output that is both digital and analog, it's pretty smart. If you plug in the special digital adapter, it gives you 5.1 spdif optical output.
I used it in analog stereo mode only, and hooked it up to 3 high power alpine amplifiers. It has plenty of output signal, I had to turn the gains down from where they were using an alpine cd player's signal.
It sounds perfectly clear, but only after windows loads the drivers for it. As the computer was booting up, there was lots of crackling, followed by a final loud POP when windows loads the drivers for it, then nothing but clear silence. I put a PAC TR-7 delay module in my amp remote line to delay the amps turn-on by 20 seconds, long enough for the computer to boot. The result = clean sound with no pops!
I recommend it to anyone having ground-loop or other noises through their onboard sound card. it's cheap, small, and sounds great.