Hi I use external USB card steinberg UR12, which doesn’t work in Manjaro.
In pulse audio in output i see only dummy output. In inxi i can see card but when i try AlsaMixer
and select that car i get this “This sound device does not have any controls.”
Steinberg UR12 is probably similar to many other audio interfaces that only have hardware controls for audio and do not need alsamixer controls
The device should be visible in ALSA for audio playback/capture:
aplay -l && arecord -l
PulseAudio will create a dummy output if there are no hardware devices available for audio playback
Check PulseAudio Configuration for device Profile. I suspect that all 3 devices are set to Off
If any audio device is changed to Analog Stereo Output PulseAudio will remove Dummy output and use the active output sink for audio playback
If USB interface Profile is changed to Analog Stereo Duplex PulseAudio will use USB interface for audio playback and capture
If you cannot find device Profile settings in audio GUI controls please post response to this command to show PulseAudio configuration
Upgrading kernel should not be necessary - Steinberg UR12 interface has been reported to work well on Linux for many years
Screenshot in OP shows that there are no audio level controls in ALSA for the USB interface
Increasing audio level is not possible in ALSA for this device, but audio levels can be adjusted using the hardware controls
If PulseAudio cannot detect ALSA hardware devices for audio output changing ALSA settings will not help