I got a microphone connected via a XLR adapter to the rear mic jack of my mainboard. The audio dialog of KDE seems to detect that, as does not mark it as not connected (which it does for the front mic and line in). But selecting the audio device as source does not produce any useful sound. What makes you sure that the mic work, you may ask? If I enable the loopback in alsamixer (and pump up the boost), it works. Unfortunately, that is the only way I can get sound out of that.

It seems, as if the system realizes two possible sources from the audio device. But there is no option GUI wise where I can select the second input to test if that helps.

alsactl info
#
# Sound card
#
- card: 0
[....]
#
# Sound card
#
- card: 1
  id: Generic
  name: HD-Audio Generic
  longname: HD-Audio Generic at 0xba600000 irq 68
  driver_name: HDA-Intel
  mixer_name: Realtek ALC1220
  components: HDA:10ec1168,10438724,00100003
  controls_count: 47
  pcm:
    - stream: PLAYBACK
      devices:
        - device: 0
          id: ALC1220 Analog
          name: ALC1220 Analog
          subdevices:
            - subdevice: 0
              name: subdevice #0
        - device: 1
          id: ALC1220 Digital
          name: ALC1220 Digital
          subdevices:
            - subdevice: 0
              name: subdevice #0
    - stream: CAPTURE
      devices:
        - device: 0
          id: ALC1220 Analog
          name: ALC1220 Analog
          subdevices:
            - subdevice: 0
              name: subdevice #0
        - device: 2
          id: ALC1220 Alt Analog
          name: ALC1220 Alt Analog
          subdevices:
            - subdevice: 0
              name: subdevice #0
  hwdep:
    - device: 0
      id: HDA Codec 0
      name: HDA Codec 0
      iface: 16
[...]

arecord -l                                            Do 14 Dez 2023 14:53:16 CET
**** List of CAPTURE Hardware Devices ****
[...]
card 1: Generic [HD-Audio Generic], device 0: ALC1220 Analog [ALC1220 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: Generic [HD-Audio Generic], device 2: ALC1220 Alt Analog [ALC1220 Alt Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
[...]

Does anyone have any clue what I could do to use that mic?