would usb sound better than a sound card


I am experamenting with pc audio and like what i hear.i am using windows vista and a sound card with coaxial out.i am using a deqx dac-it sounds very good.i was wondering if i can get better sound using a usb dac.and it seems a lot of audiophiles are making this harder than it should.i mean using foobar with this sampling rate,and doing this and that.it seems like it is too complacated.can i please get a simple version of what sounds best.thank you.
128x128gotsouldr
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.
Pschoi,

If you are using a USB DAC you will hear difference between Tiger and Leopard. The USB drviers have been updated in Leopard and sound better.
Splaskin,

Thanks for the correction - I don't have Leopard yet so I did not know that. More reason to upgrade. :)
Steve, are you sure about this? I am on Tiger and have been on the fence about Leopard, but trust your opinion since you have a Wavelength DAC. Did you really hear a difference? And how can I confirm the drivers were updated?