Enable digital audio on asus Xonar U3

I’m running Balena Sounds on a raspberry pi 3b+ works great with the usb audio in analog mode. The Asus xonar u3 has the ability to output sound via spdif digital as well, and I’d like to enable that but have no real clue how to do this. I know it’s possible after doing some searches… which although not specific to Raspian, still indicate that a special setting is necessary…

Here’s what i’ve found…

Any help or guidance here would be greatly appreciated.

Thanks in advance.


Can you elaborate on the setup a little more - not sure I have understood it completely. You have a USB DAC that outputs sound over 3.5 and spdif - you are using the 3.5 analog way, but you want to jump over to spdif for better quality - is that right?

You understood it perfectly, yes. I’d like to switch the output to the spdif for better quality.

Thank you for any help you can provide.

It seems like that usb audio card should be outputting both analog and optical spdif simultaneously. They do share the same jack though. What happens when you plug an optical TOSLINK cable (with the included adapter) into the analog audio out jack?