Hi Chris,
As you’ve seen, Roon is connecting to the 851N via Airplay. Airplay is limited in resolution (OS X downsamples to 44.1/16 when streaming with Airplay, except the Apple TV which is 48k). It seems likely that the 851N doesn’t display file resolution when rendering from Airplay (maybe try playing from a phone to check this).
Roon doesn’t support UPnP and it seems unlikely it will (see this thread for explanation):
The good news is that RoonSpeakers is intended to connect to most streamer endpoints as network zones. I’m hanging out for it too (Auralic Aries). Until then I’m connecting direct to the DAC with USB to play hi res and DSD.
I found Airplay quite laggy into the Aries. How is it with the 851N ?
Roll on RoonSpeakers !
Cheers,
Andybob