Hello,
Sorry, people!
Started my machine and today it seams everything's doing fine, again.
Can't tell you why it didn't work, yesterday, despite of rebooting twice.
The OS assigns the sound devices an index in the order they get
connected. This can vary per boot and depends of course on what sound
devices are attached at boot time. You can make this more deterministic
by forcing indexes for the sound devices. On my system I have a file
/etc/modprobe.d/audio.conf with the following content:
options snd-hda-intel index=10 vid=0x8086 pid=0x1e20
options snd-usb-audio index=0,5 vid=0x0424,0x09e8 pid=0x3fb7,0x007c
So my internal sound card gets index 10, my RME Babyface gets index 0
(so it's the default sound card) and my USB MIDI keybaord gets index 5.
You can find out the vid's and pid's of your own devices with the lspci
and lsusb commands.
Best,
Jeremy