The Nagra Streamer uses a proprietary fiberoptic cable to connect to the Playback Designs MPD-8. I do not think I can create a better signal path.
I had the lower cost version of the top end PlayBack Designs steamer called STREAM-IF. I compared it side-by-side to the Lumin X1 streamer and the older version of the Sonore OpticalRendu. They all sounded great but different which was very interesting to me since you would have thought a streamer would not sound different.
I never owned a PBD DAC (changed plans) but the STREAM-IF streamer was brilliant using SPDIF, as good as the fibre optic Lumin X1 and the OpticalRendu. Very impressed by the PBD streamer which I assume is even better with PLINK fibre.
BTW- yesterday my friend sent me a photo of the EMM top end DAC sitting in his house. He asked me if I wanted to hear it at my house. I am kind of scared to bring home a $33k DAC to my chaotic household. I have heard the PBD MPD-8 DAC, and this EMM is a direct competitor.

