Mytek Stereo192-DSD USB2 on Raspberry Pi 4 / Volumio 4.119

Diy and Tweaks Diy Volumio Projects
1

Just leaving this here as a technical note for anyone who may eventually search for this rather unusual combination.

I am running a Mytek Digital Stereo192-DSD DAC via its USB2 input from a Raspberry Pi 4 running Volumio 4.119.

The original Linux driver is the old open-source mytekusb2 driver by Jurgen Kramer, based on Torsten Schenk’s TerraTec DMX 6Fire USB driver. I updated the driver for current Linux kernel APIs and fixed an issue in the multi-stage firmware loading process where USB re-enumeration could prevent the following firmware stage from being probed.

The resulting setup has been tested with:

  • Raspberry Pi 4
  • Volumio 4.119
  • kernel 6.12.74-v7l+
  • Mytek Stereo192-DSD USB2
  • 44.1 kHz and 192 kHz playback
  • sample-rate changes 44.1 → 192 → 44.1 kHz

Playback is stable and I have not seen XRUNs during the validation tests.

One old Mytek limitation remains: if the Raspberry Pi is rebooted while the already initialized DAC stays powered on, the DAC may come back with NO LOCK. Power-cycling only the Mytek restores normal operation; the Pi does not need another reboot.

The maintained source and documentation are here:

https://github.com/jantaplick/mytekusb2

The repository does not contain the proprietary Mytek firmware files. Those have to be supplied locally by the user.

This is not a support request and I am not really looking to start a larger discussion — I mainly wanted to leave the information somewhere searchable in case another owner of this DAC ever tries the same thing.

2

Just a small update to my original post.

I recently upgraded my Raspberry Pi 4 to Volumio 4.204 / Nova 0.261001.0 , which also changed the kernel from 6.12.74-v7l+ to 6.12.75-v7l+ . As expected for an out-of-tree kernel module, the previously built Mytek USB2 driver no longer loaded after the update.

Fortunately, the driver itself did not need any further source changes. Rebuilding the existing patched snd_usb_mytek module against the exact new Raspberry Pi kernel source and matching symbol versions was enough.

I have now tested the setup again with my Mytek Stereo192-DSD : firmware loading works automatically, Volumio playback is stable at both 44.1 kHz and 192 kHz , switching 44.1 → 192 → 44.1 kHz works correctly, and the module also loads automatically after a clean reboot.

So the current validated setup is now:

Raspberry Pi 4 + Volumio 4.204 + Linux 6.12.75-v7l+ + Mytek Stereo192-DSD USB2

The only old limitation remains: if the Pi is rebooted while the already initialized Mytek stays powered on, the DAC may need to be power-cycled afterwards. Once that is done, the firmware sequence starts automatically again.

I have also pushed the updated Volumio 4.204 packaging branch and a new v2 tag to my GitHub fork:
https://github.com/jantaplick/mytekusb2

Maybe this is useful for the few other Stereo192-DSD owners still using the proprietary USB2 interface.