I agree with Gmood1. Try a Paradisea DAC. Yes it uses a tube, but as a buffer. Only one tube. No biggie. It does what you describe as your goals. Inexpensive, too. Hook it up to your Modwright with glass Toslink cable available on Audiogon for $20 and away you go...
Don't like it? Try another DAC.
Don't like it? Try another DAC.