Of course, the general answer is "it depends on the implementation of each". But a few rules of thumb are useful and I am very familiar with the denefrips.
1. Toslink is always inferior. I wont get into detail on why, but both jitter and sampling rate are worse. Pretty cut and dry. Its great when EMI immunity is required.
2. While there are different profiles, and i’m peaking very loosely, in general SPDIF depends on the clock of the sending unit and USB is asynchronous, mostly, so timing is by the clock of the terminating unit (DAC). Since the denefrips DAC’s timing ( and most of it) is vastly superior to the Node, you want the Denefrips in total control. This means USB. Any quality cable will work fine.
Important note: But you still have some ground noise issues with this direct connection, so.....
The best is to run the streamer via ethernet to a fairly quiet (electrically and mechanically) bridge that terminates the ethernet (isolation) and spits out the USB High res profile 2 data. Make sure this unit has a quiet, linear power supply. The denefrips has, again, an isolated USB interface, which helps and will re-clock and read out everything. This is how i run:
- ROON ROCK streamer
- Custom modified Raspberry Pi runnign Roon Bridge, with a cusotm made low noise linear power supply
- USB cable to Denefrips (apple if you care, i dont)
Voila. Superb.
G
