How important is direct USB connection into DAC?

My current system is PC (Windows XP 2000, service pack 3) out to Behringer U-Control UCA202 via captive USB; stereo analog RCAs from Behringer out to Parasound analog pre-amp into NAD 2 x 90W amp. Speakers are Polk M50 floorstanders and Sony 100w x 10" sub. AOL Radio and my library of downloads sound great, but I know it would sound better if I added a 24/192 DAC.

If I get a USB DAC, I can eliminate the Behringer. This is my preference. However, non-USB DACs are, generally,less expensive. If I get a non-USB DAC, I can run an optical from the Behringer into the DAC and then RCA the DAC into the Parasound.

Would the direct USB to DAC route be sigificantly better than the indirect route?
Depends entirely on the USB interface. They are not all equal. Chips are different, USB software is different and implementation is different. You can still run USB to your non-USB DAC using a USB converter. Some are excellent, even better than the USB interfaces on some USB DAC's. Here are some options that were recently reviewed:

I would avoid adding the Behringer in the mix. Just do a USB DAC or USB converter to a non-USB DAC.

Steve N.
Empirical Audio
What are some examples of good USB converters? Can I expect decent results with USB out > USB converter > non-USB DAC?

If you check out the link provided by Audioengr, above, you'll find four current USB converters and a pretty clear review of the results. There's only one I know of that I would want to add, and that's the Blue Circle Thingy (which will also function as a DAC while you save for your dream outboard converter).

Briefly, yes the results are decent and can be very good indeed.
Go with Firewire! Much better than USB. I have an M Audio Firewire Solo ($200)- converts Firewire to SPDIF and than get ANY dac you want. Firewire, fireire, firewire!
Tobias - it's too bad he didnt review the Thingy, but the results can be predicted. It uses the same hardware as the HagUSB and Trends.