The Motu AVB line of interfaces sopposedly works class compliant. Unfortunately, when trying to use them class compliant, the USB-audio hops between channels, mixing up byte-order of channels in %8 channel counts. This renders class compliant mode not usable, since even if you managed to externally mix all %8 output channels, you would still get the hurtfull artefacts of sound being output with (what to me sounds like) wrong byte-order.
This issue has been discussed elsewhere in forums and @drumfix has written a linux-driver that works with the proprietary mode of these interfaces. To use this driver, the linux-kernels USB module must be altered. Instructions exists on @drumfixes github-project but I have not yet found a patch that could be applied automatically and be used in automated settings, e.g. distributions.
This is me trying to get these interfaces working in my (FLOSS-powered) studio.
Patching the kernel
https://github.com/Drumfix/motu-avb-usb/issues/1#issuecomment-839164217
- recompile the kernel