This has proven to be a very informative thread as I have been trying to figure out which method of connection between Mac mini (music server) and Meridian 568.2mm Processor is best:
(1) Mac mini > Toslink > Meridian 568.2mm (currently used)
(2) Mac mini > USB > Singxer SU-1, Gustard U16, or Schiit EITR > SPDIF > Meridian 568.2mm (considered “upgrade”)
Given that various tests show that the implantation within the DAC/Processor is paramount I am leaning towards continuing to use Toslink as the Meridian unit uses high quality implementation and is specifically designed to de-jitter incoming digital signals and upscale everything to 24/96.
Just not sure there are actual (audible) advantages to the asynchronous connection provided by USB-to-SPDIF conversion (e.g., Singxer SU-1, Gustard U16, Schiit EITR) over a straight Toslink connection into a well-implemented DAC/Processor?