USB soundcard only works with manual config

[ericvmueller]

I am running a raspberry pi 4 with version 3.9.6 of balenaSound. Everything works fine with the headphone jack, but when I plug in a USB soundcard I don't get any audio.

I can fix this in the alsamixer on the audio service terminal in balenaCloud. I need to manually switch the output from the headphones to the USB soundcard, and I also need to increase the volume from 0 (despite having already set SOUND_VOLUME to 75, which works for the headphones).

I would like to know if there is a way to ensure this configuration is set upon system boot, so I don't have to go into the CLI every time I start up my system.

[plisker]

#496 (comment)

I was able to permanently set my USB soundcard with this route!