Discrete R2r With Tube Output

I have the Lab 12 DAC 1 Ref.   It really sounds good.  Something that should be auditioned or have an easy return policy.   I listened to a few DACs below , at , and above its price.   Loved its sound and can live without DSD and fixed output. Which I prefer on a source anyway. Not for everyone but a really nice sounding DAC. 
 

Maybe DSD is why he wants a FPGA type DAC….

The Wells Audio Cypher Dac is fantastic and uses the latest Sabre pro dac chips.

good luck on your search.

@glennewdick 
I just got that LTA Aero Dac and its incredible. Excellent resistor chip and there's no beating a David Berning tube stage of power supply.

Lampizator 

I was just at the hifi show and that LTA aero was in a couple rooms, sounded really good, very smooth and analog.. and it looks really cool