We have a very in depth review coming out on the Bryston BUC-1 USB Interface.
As a sneak peak here is a short excerpt:
After 4 days of running tests for the Bryston BUC-1 I have the test results, and they are really something.
At 24/96 sampling, THD+N at 1 kHz was 0.00002%, which is below any digital product I have ever tested.
The clocking procedure is superb. I think consumer who already have a DAC with an asynchronous USB input might want to put the BUC-1 in the signal chain, with the computer output to the BUC-1 and the BUC-1 to their DAC., and yes, the sound is great!