I cannot seem to find a way to get windows 7 to use the fireface 400 as the default sound device. I had it working earlier today but I either uninstalled something or did something else (maybe uninstall nvidia HD audio) or something and now it is not working ! I cannot seem to get the fireface to appear on the device list for the sound devices.
Disable any other sound cards in Device Manager , then reboot .
I’ve now managed to get the device working. I had to re-install the drivers. Not sure what happened but at least it’s sorted.