Best tube dac available?

The Ayon makes a nice tubed DAC; with full array of digital in/out..and up samples.. I have the Ayon CD5-5; integrated transport and DAC with tubes; and quite happy with sound when used with my Qsonix music server...much better than the PSAudio it replaced..I believe their stand alone DAC is the Spirit or Orien..not sure name...

Eastern Electric Minimax DAC + opamps

The Audio Research DAC8 that I own is not tube based. After much research and testing they found solid state DAC's are better sounding.
The DAC 8 is the best sounding DAC I could find regardless of price or technology.

Solid State DAC's certainly test better- no arguement!
It is usually the Analog Output Stage and/or Rectifier
that is Tubed on a Tube DAC. Listening is the same
subjective arguement that has been the bane of Audio
ever since Solid State first challenged Tubed Equipment.
There are some things that Tubes do better, others that
Solid State does better! Some try to capture a little of
both! The BEST Solid State Devices might be stratospherically beyond the budget of many. Tubed Version
that might get you 95% of the way there at 2/3rds cost,
might be ticket for many. Talking of the heaviest Iorn
Solid State out there- of course there are expensive Tubed
Units as well.

there is a thread that is running now regarding the amr 777 dac. peerhaps that could be added to your list of candidates.

agian your criteria of sonic excellenece is the salient fcator when considering what is the best sounding dac.

there have been and will be threads which ask the question :

"what is the best ..... ?"

i think such a question is rhetorical and the questioner should consider it as a quest to listen to as many components in one's price range.

if one does not have access to products, then one is being exposed to the risk of disappointment.

well intentioned audiophiles who make "helpful" suggestions do not remove the probability that following one or more of them will lead to disappointment.

there are no guarantees in life.

my personal philosophy is to speak to manufacturers and inquire as to what they think their products sound like or what they intend them to sound like, and go from there.

there is a trade off between personal experience of owners and statements from designers. there are many variables here and no easy answers.