Multichannel in Linux

Does it work over HDMI? I have a Raspberry PI3 and Odroid C2, but not sure how to get this working to my Oppo 105D?

It should work out the box. If you’re using DietPi (highly recommended) just ensure that in settings HDMI is not turned off. You should be able to select the HDMI output as an endpoint.

Trying for two days to get DietPi running. Still no luck.

Finally got DietPi Stretch up and running using a 16GB card (it failed many times trying a 8GB card), but it only shows 2 channel for HDM and only 44.1 and 48. What have I missed?

I have tried both “rpi-bcm2835” and “rpi-bcm283-ultrahq”.