08-Feb-2019, 17:18
@alandbush is right: a USB device has a set of descriptors that advertise its capabilities. For an audio device this includes combinations of sample rates and bit depths it is able to support. The connected USB "host" (the Lumin in this instance) reads these descriptors when the USB connection is established and can then select which sample rate/bit depth combination to work with.
Roon (Mac Mini), Wilson Benesch Full Circle, Expert 1000 Pro CI, Kaiser Chiara
Warwickshire, UK