I’ve had to replace my original Asus Xonar U7 USB DAC with a new one. For the last few months it has refused to reset properly and would only do so when warm air was blown onto it for a couple of minutes! (I don’t now know how I discovered that, but it always worked). I have a feeling that there was always something marginal about that design’s reset, having experienced a problem the first time I used it, but then it worked fine for a few years.
Archimago once mentioned something about the reset of that chipset being dodgy, too.
The new one is the MK II version and I had to change a single item in the software’s config file: its name as discovered by Alsa is ‘MKII’ as opposed to the previous ‘U7’. Also, the sequence of jacks on the back has changed, as seen by my software.
It sounds just the same as the Mk I and thankfully seems to reset every time.
The Rational Audiophile 