MSI MPG B650 CARBON WIFI (USB ID 0db0:70d3) - Front panel headphones detected but no audio output

[GitHub issues - opened <github@alsa-project.org>]

alsa-project/alsa-ucm-conf issue #818 was opened from mtr-rdr:

### Summary

I believe I may have found an unsupported or partially supported MSI USB audio device.

My motherboard is an MSI MPG B650 CARBON WIFI (MS-7D74). The onboard audio appears as a Generic USB Audio device (USB ID 0db0:70d3).

Under Windows 11 the front panel headphone jack works correctly.

Under Linux Mint 22.3 the headphone jack is detected correctly, but no audio is produced from the front panel headphones. The rear speaker outputs continue to function correctly under Linux.

I am unsure whether this is a UCM issue or something lower in the stack, but after several days of troubleshooting I noticed that USB ID 0db0:70d3 does not appear in the current ALC4080 USB-Audio.conf profile while many other MSI ALC4080 boards do.

I would appreciate any guidance on whether this is expected, or whether support for this board is currently incomplete.

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### System

- Distribution: Linux Mint 22.3 (Ubuntu 24.04 based)
- Kernel: 7.0.0-28-generic
- Motherboard: MSI MPG B650 CARBON WIFI (MS-7D74)
- USB Audio Device ID: 0db0:70d3

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### Behaviour

**Windows 11**

- Speakers work.
- Front panel headphones work.
- Plugging headphones mutes the speakers automatically.

**Linux Mint 22.3**

- Speakers work normally.
- Headphone insertion is detected.
- PipeWire switches to the headphone output.
- Front panel headphones remain silent.

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### Troubleshooting already performed

- Confirmed the hardware works correctly under Windows.
- Tested multiple PipeWire output selections.
- Confirmed headphone jack detection works.
- Tested playback directly with speaker-test (bypassing PipeWire).
- Inspected ALSA mixer controls.
- Compared available mixer controls against the existing ALC4080 UCM profile.
- Verified that USB ID 0db0:70d3 is not currently included in USB-Audio.conf while many other MSI ALC4080 boards are listed.

I have attached a complete diagnostic report containing:

[audio_bug_report.txt](https://github.com/user-attachments/files/30364459/audio_bug_report.txt)

- ALSA card information
- USB descriptors
- aplay output
- amixer controls
- PipeWire status
- Current USB-Audio.conf

If additional diagnostics, testing, or patches would be helpful, I would be happy to test them and report the results.

Thank you for your time.

Issue URL     : https://github.com/alsa-project/alsa-ucm-conf/issues/818
Repository URL: https://github.com/alsa-project/alsa-ucm-conf