Hello,
i am successfully using the HiFiBerry DAC+ and a Raspberry Pi for a synthesizer project which is a live-coding collaborative spectral synthesizer, visuals are generated by a GLSL script and fed to the Raspberry Pi through the network, the RPI is used as a raw additive synthesizer with up to ~700 simultaneously playing pure tones oscillators at the moment, the DAC+ is used to output the result to my fx processor/equipments.
Here is some videos :
https://www.youtube.com/watch?v=au7ndaEoY1E
https://www.youtube.com/watch?v=7x9S0sCz2GU
This setup was done in a single week and i plan to do a bit more with the RPI and DAC+! :)