would usb sound better than a sound card

If you stay PC (noticed, like me, that you ae thinking of making the switch to a Mac, assuming all is simpler and purer there) I'd give a listen to this:
1)EAC to FLAC (lossless open-code that has a Mac version too)
2)FLAC playback through Foobar 0.8.3 (older version, still sounds best), with the SSRC 24/96 upsampler plugin in Foobar
3) Out to your great PS Audio DAC III (USB doesn't like 24/96, so I'd try coax out w/resampling vs no resampling-with-USB; one choice will be better)

It's what I do (non-USB dac currently), but I'm gonna demo the Wavelength USB Dacs, and Gordon says I should go Mac. My own problem is when i ripped in FLAC I ripped to large album files and use CUE sheets (associated file that has all the tags, etc. and Mac doesn't support that mess). If I go MAc I'll use itunesencoder.exe and batch convert all to Apple Lossless and use iTunes on Mac.

Once you go MAC with a Wavelength DAC...You ain't NEVER goin back. : )

Longtime and Proud Cosecant (V2) owner. Last source I will ever need.

CDP's are dead to me.

Get MAC with PS audio USB DAC if your budget is limited. But if you can afford Wavelength go for it. MAC+WAVELENGHT can't go wrong with this set. Have fun! Enjoy.

ok great,thanks for the responses.now i like the idea of a mac but which one and what software version,panther,tiger?thanks again.

Gotsouldr, if you plan to buy a new Mac, then it will come with the "Leopard" OS. If you have an older Mac or plan to buy an older, used Mac, then it may come with Tiger or Panther. Regardless, you should be able to run the latest iTunes with it. Mac OS older than Tiger will not support "Front Row" remote-control capability (there is a workaround).

Sound-wise, I do not believe there are differences between late model Mac OS'es.