Which output do I use on Roon if I want to use my core as an endpoint. My choices are system output, built-in output, and HDMI. I can’t get audio out of any of them.
If you just want to use the headphone jack, System Output should be sufficient.
If you want to use Exclusive Mode (meaning higher quality output, but no other applications can play to the headphone jack while Roon is playing), you can use the Built In Output.
What have you tried so far? Let us know and @support can help.