Dated but still A rated DACs


Looking to purchase a great sounding used DAC , unless I can obtain equal quality on a new one. Your thoughts?
goldenear1948
Ayre QB-9 DSD (upgraded from the original Ayre QB-9) I've been upgrading my Ayre with SR fuses (current Blue) and added the Uptone Audio ISO Regen with the LPS 1.2 linear power supply. I also put an Akiko tuning stick in one of the Ayre XLR inputs. It's very neutral and transparent without sounding cold. Audirvana Plus is 100% compatible with my DAC and the upgrades. I'm running my Ayre DAC through an ASR Emitter II Exclusive amplifier and through a pair of Quad 2905 ESL's.
  I should have mentioned probably one of the best bargains for a dac, the Monarchy NM24. People don't go after it because the name doesn't impress their friends but that thing runs PCM-63's and I have owned it before. 

Actually, the NM24 used the 1704. It is the M24, which I have, that uses the 63.
Anyone use a Muse Model Two to stream and if so how did you integrated it into your system?