A warm DAC?

Didn't Metrum close down?

any of the Denafrips DACs. The Ares is a beauty for the price.They tamed the highs in my system. No loss of them, just better controlled and less fatiguing

Went from a Schiit Gungnir Multibit (R2R chip) to a Lampizator Amber 3 (DS chip + tubes) and it does everything so much better. I was shocked by the improvement having heard only small differences between dacs before. And I used to be a stickler for R2R. Not sure how it measures but it sounds incredible. And yes it did smooth out the top end without taking away detail and clarity (if not adding more).

Point being that you should focus on the sound, functions you require, and synergy with your other gear ... instead of underlying tech (or lack thereof).

Larseand,
    I have a PrimaLuna EVO 100 Tube DAC. It is definitely on the warmer side. PM me if you are interested in more info. 

I would second the R2R path. I recently did a post comparing Denafrips AresII with a Topping. I guess I cannot definitely say it is the fact that it was an R2R, but I would describe the sound as producing more natural sounding instruments.  Not sure what is meant by warm but if it's analog and natural or palpable, this DAC did that, for me.