Hi, the Primo (as Gé said) does not need a DAC, since it features an high quality DAC.
But you can always add your DAC via USB or SPDIF output.
No, it does not accept SPDIF input
I read all it’s tech specs and you can use it single solution as Network streamer + DAC with built in Wifi or you can use it as a streamer via it’s USB to an external DAC if you have a better DAC product. Please correct me If I’m wrong because this is what I understood from reading it’s specs.