Note that there's nothing at all in modules.conf
for the
Radium keyboard. It's simply a MIDI controlling keyboard,
it makes no sound on its own, it would be used simply to
control soft synths on the PC.
Anyway, you need the module snd-usb-audio for it, because this
module handles MIDI as well as audio over USB. On ALSA,
there's no singular dedicated usb-midi-module to only handle
MIDI data (AFAIK in older ALSA versions usb audio and midi
have been two different modules, but this has changed).
I believe
snd-usb-audio supports up to 8 devices, so you
should be able to define the 2 you are using to control
the order in which they appear on your system.
I'll definitely take a look at this approach, as well as
modifying an asound file.
The file has to be created, it does not exist per default.
I have two USB cards and do not use an /etc/asoundrc
Best regards
ce