Hi @DiscoFerret, and welcome to the forums! The dtoverlay value for the Allo Piano 2.1 can be found in the manufacturer’s documentation; on that page you’ll find a link called “Configuring Allo Audio Cards for Raspberry Pi”. In there, it says that the dtoverlay should be set to allo-piano-dac-plus-pcm512x-audio. You can try that value in the dtoverlay setting for balenaSound.
As it happens, another user recently posted about the same card. They were able to share that it works, but certain features related to the subwoofer don’t work without firmware files from the manufacturer.
Give that a try and let us know how it goes – if it works for you, we can update the balenaSound documentation to include that DAC.
All the best,
Hugh