Best Dac under $600... New or used

I'd start with the used benchmark and build around that as needed.

As a tubeophile, I found the benchmark to be too stark, too detailed on the detailed - musical continuum scale. I'd suggest the Eastern Electric MiniMax I with upgraded op amps and an upgraded 12AU7 type tube for $600 used with a volume control.Very nice.

Not that the benchmark is less than a good product for the money, I have seen many (as Truman above) on this forum characterized it as bright or analytical. It remains a popular DAC however. As one that has a system based on a digital front end feeding a tube pre/SS amp combination, if I was using a DAC to feed directly into a SS amp, particularly an inexpensive one, I would look into one having a tube output stage. I prefer a warm sound over a overly analytical one and I have found tubes to provide this, especially with digital audio. As I have not auditioned any such DACs, I can’t make a specific recommendation. However, I have seen others mention liking the EE DAC on this forum.

Good luck in your search!

Schiit