Re: USB ALSA card number

Hi,

I'm using the below /etc/modprobe.d/alsa-base.conf file.

It contains 2 instances of snd_ice1712, but just one of those cards is
actually built-in, so no card can become hw:2.

You can also add snd_usb_audio as a placeholder.

[rocketmouse@archlinux ~]$ cat /etc/modprobe.d/alsa-base.conf 
# ALSA module ordering
options snd slots=snd_hdspm,snd_ice1712,snd_ice1712

[rocketmouse@archlinux ~]$ aplay -l # USB audio interface isn't attached
**** List of PLAYBACK Hardware Devices ****
card 0: HDSPMx579bcc [RME AIO_579bcc], device 0: RME AIO [RME AIO]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: EWX2496 [TerraTec EWX24/96], device 0: ICE1712 multi [ICE1712 multi]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 3: HDMI [HDA Intel HDMI], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 3: HDMI [HDA Intel HDMI], device 7: HDMI 1 [HDMI 1]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 3: HDMI [HDA Intel HDMI], device 8: HDMI 2 [HDMI 2]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 3: HDMI [HDA Intel HDMI], device 9: HDMI 3 [HDMI 3]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 3: HDMI [HDA Intel HDMI], device 10: HDMI 4 [HDMI 4]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
[rocketmouse@archlinux ~]$ aplay -l # USB audio interface is attached
**** List of PLAYBACK Hardware Devices ****
card 0: HDSPMx579bcc [RME AIO_579bcc], device 0: RME AIO [RME AIO]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: EWX2496 [TerraTec EWX24/96], device 0: ICE1712 multi [ICE1712 multi]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 3: HDMI [HDA Intel HDMI], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 3: HDMI [HDA Intel HDMI], device 7: HDMI 1 [HDMI 1]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 3: HDMI [HDA Intel HDMI], device 8: HDMI 2 [HDMI 2]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 3: HDMI [HDA Intel HDMI], device 9: HDMI 3 [HDMI 3]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 3: HDMI [HDA Intel HDMI], device 10: HDMI 4 [HDMI 4]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 4: USB [Scarlett 18i20 USB], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
[rocketmouse@archlinux ~]$

Regards,
Ralf