Hey Viggen, I had an NEC Multi for about a year, same $20. thing was built to take it. I cleaned out all the ancillary wiring, there was a choke in there I replaced, and gave it a nice SPDIF input jack. Also, a better Atari PSU.
I thought I got the idea from you, but now remember I originally got the idea from some article, I believe in Positive Feedback. My results were similar to those of the article: it was fantastic. It was even better than the Sony 7700 to me. One day it just stopped, after a million CD's. I never went back to find another one. I think I will. Maybe build a nice "analogue looking" wooden box for it, I kept the darn thing too, I can use the black faschia again. I installed the Nixon in a very nice tooled wood stash box, sandwiched between two layers of isolation foam. -A good home for it, with Isis' eye staring out, in brass.
Have a look inside it, you will see the opp. to redo some minor wiring. It made a huge difference in the overall transparancy and coherency, especially in the mids, as I recall. Keep us updated.-..