I tested for you the D50 from Topping with Volumio
It work perfectly with Volumio, and recognised. Just select the Dac for the output, and let’s go !
I love this D50, very intresting DAC, with a very good renderer with a hi-def sources
i have also a D20 from topping, Also recognized by volumio. An older DAC, with less quality regarding the D50, but intressting never the less.