A Raspberry Pi-based setup is probably going to be the best (or at least most flexible) option as long as you don't need AirPlay 2. I really wanted it, but after looking through literally every AirPlay 2 supporting device I could find (at least going by the list Apple maintained), I ended up giving up and just built a RPi4 + HiFiBerry DAC+ XLR to use with my LSR305s (which basically requires using a balanced connection to not have to deal with the annoying buzzing). AirPlay (1) works fine, and who knows, maybe something will eventually come out of AirPlay 2 being cracked and we'll see open-source implementations for that too.