Hi
So I either did something wrong, or I'm misunderstanding what I can do with this.
The latter, see the documentation.
RuneAudio is booth hard and software.
You only can play music though a soundcard attached to your PI.
From the documentation:
At the heart of your digital hi-fi system
A RuneAudio device places itself at the heart of a digital music system.
A streamer player:
It can reproduce your digital music library from local USB drives or network mounts (NAS), and also plays any internet stream (web radios).
A headless player:
It can be remotely controlled by multiple clients running on different devices.
A digital player:
Staying at the top of the audio signal flow chain. It offers perfect and gapless playback of common audio formats, RuneAudio works best when connected to an asynchronous USB 2.0 DAC, an I2S DAC, or a S/PDIF output to a DAC.
Frank