IME, one of the reasons to use the mR (or something like it) is to eliminate noise from the server PC as a factor in your USB playback. The mR makes server tweaks unnecessary, or almost unnecessary. I've tried using different PS etc on my server with the mR in line, and haven't noticed any difference in SQ. Before using a "2 PC" solution, I did hear a difference when using a superior PS on the server.