What is the best DAC to buy used in the $500 range

I was in the same situation 6 months ago and my research lead me to the Bel Canto DAC rev 1.1 - the .1 is an power supply upgrade from the original. The BC DAC retails for 1300.00 and they can be acquired on A'gon used for 500-600 dollars. Do a google seach a read the reviews -the BC is an excellent performer

NOTE....which ever DAC you settle on be sure to pair it with a high performance digital cable. When I initially purchased my DAC, I bought a well reviewed budget digital cable and at the time though it was a good performer...that was before I auditioned a Transparent digial reference cable -the difference was night and day. I never would have imagined that swapping out 1 cable would make such a difference, but it does, at least with my setup the diferrence was audible.

Good luck!

please disregard the subject line of my previous post "rotel rb-1080 hmmm" looks like the line was copied from a previous post. The line should have read Bel Canto Dac 1.1...thks

I second the Ack dAck recommendation. I have it and have compared it to a few high $ units (Cary, Meridian) and it comes through with shining colors. Terrific analogue-esque sound. The new version is supposed to be even better, but for the $450 or so you will pay for a used one, I think it is a true audio bargain...

First, decide on what features you need, volume, toslink, coax, multiple inputs, hdcd or....
Secondly, do you want tubes or solid state?
Third, do you like warmer sound, analytical or ???
Fourth, do you need 24/96 or will a great 20 bit unit work?
Finally, looks: Do you need it to match your system?

The Audio Mirror D1 DAC is awesome. I'm glad I bougt it and am considering selling my Nixon and buying another one.