this is the output of /proc/asound/modules
0 snd_bcm2835
1 vc4
2 vc4
3 snd_usb_audio
I want usb as default and put it to /etc/asound.conf
defaults.pcm.card 3
defaults.ctl.card 3
Problem is that after every reboot the usb device number changes randomly between 1 and 3.
I tried with different numers in /lib/modprobe.d/aliases.conf which had basically no effect.
options snd-usb-audio index=-2
What can I do that usb audio becomes tue default?
To enforce a certain order of sound drivers, use the slots option of the snd module:
options snd slots=snd-bcm2835,vc4,vc4,snd-usb-audio
Independently from that, the defaults.xxx.cards settings also accept the card ID (which is found in [brackets] in /proc/asound/cards).