Don't take this as critical, it's simply my take. I think you need to look beyond the vacuum tube. I use tubed pre, phono, and mono blocks.
In the DAC world some might say the analogy of solid state and tubed is sampling and non over sampling or NOS, and like everything else not all NOS DACs are the same.
IMO some of the latest DAC designs at all price points are becoming more analog like in their presentation. I would stay away from older designs like the plague.
The key is in doing your own research here, AA, and The Computer Audiophile.
Recently DSD capable DACs capable of high (24/348?) are coming into their own. I know you don't see any practical need for DSD but they seem inherent with other sonic virtues. Mytech comes to mind.
Good luck with it.