GSX 1000 Issues Upon Reboot

I have my Sennheiser GSX 1000 External DAC/AMP setup through editing the pulseaudio config. I can run the command "aplay -1" and I can see my GSX on devices 1,0 and 1,1 but when I reboot the system and run the command again the devices move to 3,0 and 3,1 causing pulseaudio to break. I can run "alsa force-reload" and my GSX is back to devices 1,0 and 1,1 so I have sound again. Can anyone tell me why my GSX is changing device card id when rebooting and what to do to stop it?

1 Answer

When the system is booted, the first sound card number is assigned to the first driver that happens to report that a device has been found.

To prevent other drivers from getting the first two numbers, add the following to some .conf file in /etc/modprobe.d/:

options snd slots=snd-usb-audio,snd-usb-audio

To fix the order of the two USB audio devices, add the following line:

options snd-usb-audio index=0,1 vid=0xAAAA,0xCCCC pid=0xBBBB,0xDDDD

where AAAA…DDDD can be found in the output of lsusb:

$ lsusb
Bus *** Device ***: ID ****:**** Linux Foundation 2.0 root hub
Bus *** Device ***: ID AAAA:BBBB The Hub Audio Thingy
Bus *** Device ***: ID CCCC:DDDD Sennheiser GSX 1000
Bus *** Device ***: ID ****:**** USB Toaster
...

See for a longer explanation.