I just bought a RME Fireface UCX and switched it into class-compliant mode
under debian wheezy. You can do that by pressing the so-called rotary encoder
twice then switching it until the display shows CC.
Then plugin the Fireface into the USB-Slot.
Automagically it will appear in the sound device selection in KDEs
systemsettings. If you choose it as preferred output device for music etc. and
maybe switch the audio device in an audio player such as vlc you will be able
to enjoy the sound of the fireface in debian wheezy!
yippie! no need for tweaking source codes ;)
I didnt check out inputs yet. I will let you know when I did!