I think tubed Dacs with capacitor coupled outputs are the norm actually. In terms of transformer coupled output Dacs Audio Note and SW1X come to mind.
Tube DAC without output transformer?
Which ones exist, regardless of price? I know of the Aqua DACs, which use a tube-mosfet type output stage. This fits the bill because it lacks a traditional output transformer. I believe most other DACs that have tubes use output transformers. In essence, I am looking for an OTL DAC.