Best used DAC under $750.

I'll be listing my Eastern Electric MiniMax DAC Supreme shortly for $595.00
I believe that it retailed for $1300. new. It has both tube and SS output.
I don't know much about the others that have been suggested here although I can safely say that the EE blew away the DAC in my Sony SCD-C555ES CD player. It has XLR out as well. Check it out.

Used: Schiit Gungnir Multibit Analog 2

New: Schiit Bifrost 2 (as recommended above).

If I was in the market, I’d get the Bifrost 2 and be done with it.

I have been happily using Bryston BDA-1 since 8 years. Currently there are atleat three offers on A’gone which can fit your budget ( under $700) comfortably.
Bryston gears are very reliable and long lasting. I would recommend to consider it.

If you are happy with redbook only,  then do your best to find a Wadia 15  It uses the Burr Brown PCM63 R2R architecture which beats, to my ears, the delta sigma DACs, unless you are prepared to pay huge money.

This on redbook is a more musical and rewarding experience than my Bryston BDA-1 playing hi-res.  The Wadia is built like a tank and can be found for about $700 to $1100

A friend brought his Theta over to compare. He went very quiet when he heard how much better the Wadia is.

Hello,

I’m about to upgrade and I have a Chord 2Cute which a great DAC. I will let it go for $600.00. You can send me a message or email me at tbrathw8@gmail.com