It’s super easy but watch out because volume levels are messed up (super loud on tiny volume values!).

Flash the image with RPI imager (enable SSH)

/boot/config.txt might need dtparam=audio=off but I don’t remember, try without that change.

Boot the device

Visit http://moode.lan (or fix your network, use the IP etc) and click “m” -> “Settings”

“Audio” -> “Audio Output” -> “I2P”: Select “HifiBerry Amp2”

Restart

Use your favorite MPD client (or the web UI) to play some music (FIRST SET A LOW VOLUME for safety, 100 is insane here, ~20 is room level). It should work already, if not, troubleshoot.

“Audio” -> “ALSA Options” -> “Max volume (%)” seems to do nothing

“Audio” -> “MPD Options” -> “Volume options” -> “Max MPD volume”: Set to 30% so at least in the Web UI of moOde you won’t be able to kill your speakers.

In your other MPD clients, make sure you never set a high volume…

Music on connected storage will be discovered automatically and added to your library.