If you have a minute, could you please check the level
of cpu usage while
using your quattro? Fex. when playing a cd, or better yet some 4-channel
stream, which is uncompressed so that almost the cpu activity will be due to
the usb bus activity. If it's negligible on your system, it should be so on
mine too.
I'd also be interested in knowing the figures. Are you using all four channels
of audio in and out simultaneously, m?
Cheers
Daniel