brab

Not exactly what you're asking but I've compared the rdac coupled with an ancient Rotel 965 as transport with the NAD you mention using both the NAD as transport with the rdac, and the NAD alone. The rdac-Rotel was much better in both comparisons.

If I understand the reviewer correctly he has compared the various computer to rdac inputs and finds the USB to be the best. I have not compared computer to rdac inputs, but have compared the computer to rdac USB connection with my Rotel 965 to rdac connection using the Rotel as transport and connecting its coax out to the rdac coax input. In this comparison I much prefer the Rotel to rdac connection whether I'm using the computer's optical drive, or hard drive file to rdac. I would have thought that the asynchronous USB input to be superior, but not in my experience.