Hi Norm, USB straight out the computer has always been pretty horrid for me.
First, I'd recommend an interface to isolate the USB and reduce USB noise - the iFi iUSB and Schiit Wyrd do similar jobs.
In terms of USB-S/PDIF converters, there are so many out there at the moment, you could take your pick at any price level. A lot may depend on what your ML sounds best with. For USB-RCA, I'd recommend the iFi iLink, for USB-BNC, I'd recommend the Audiophileo, and for USB-AES, I'd recommend the Yellowtec PUC2 Lite, which I currently use with my NAD M51.
First, I'd recommend an interface to isolate the USB and reduce USB noise - the iFi iUSB and Schiit Wyrd do similar jobs.
In terms of USB-S/PDIF converters, there are so many out there at the moment, you could take your pick at any price level. A lot may depend on what your ML sounds best with. For USB-RCA, I'd recommend the iFi iLink, for USB-BNC, I'd recommend the Audiophileo, and for USB-AES, I'd recommend the Yellowtec PUC2 Lite, which I currently use with my NAD M51.