Dated but still A rated DACs

I'd try a used Metrum Hex DAC or used Bel Canto DAC 3.7 or 3.5 but only the VB models with the Virtual Battery Supply.  Both have gotten reviews that put them on the level of much more expensive DACs.  I had the DAC3 VB in my system for a bit, and it was extremely good.  

I consider Mytek's fairly new, and very good sounding.

Theta's always sound good too. An underrated performer, the Casanova, goes up to 96kHz/24, and does sound much better on hi-res than Redbook.

Benchmark DAC2 if you have an integrated or a preamp, or DAC2 HGC if you don't.

I love my Luxman DA-06.   Typically sell for $2,500 used.