Wired through UniFi switches
Raspberry Pi 4 running RoonBridge on Ubuntu 21.04
MOTU UltraLite-mk5 running at 192kHz connected to the RPi4 by USB
How would I know?!
This configuration works fine apart from the fact that any unused channels are filled with a loud static-like crackle. So if I configure the device channels in Roon as 2.0 then channels 3 - 10 are filled with noise. If I send 5.1 or 7.1 sound, those channels play back fine but the unused channels contain noise. If I configure it as 7.1 and send stereo, for example, as 7.1, then channels 3 - 8 are silent but 9 - 10 are still filled with static. And with 5.1 I get four channels of noise. If Roon could send 10 channels, I’m sure there’d be no noise at all!
There are no specific ALSA configuration setting on the RPi4. The UltraLite has no drivers installed under Ubuntu.