Rogue DragoN or Bel Canto Ref600 M

Now that I look closely at the Rogue, it too probably has opamp buffers (circled) to drive the Hypex NC500 modules with.
https://ibb.co/S0ZySr7
With just maybe the tube as input for the buffer to give some tube flavour, good thing is that "could" be switchable bypassed by a good tech.
And would result similar to Belcanto then but with linear supply my preference.

Cheers George

Consider PS Audio M1200s, which have a tube input

I’ve had full tube rogue gear for years, like 20 years. I’ve not heard the dragoN but have read a lot of good press on it. One of the things I like about rogue is that, while it’s tube based gear, it’s not overly "tube sounding." It tends to be very neutral and punch way above it’s weight class. I would say that if you want the option of tubes in a preamp later on, go with the Rogue. Their RP line is stupendous. My RP-7 is amazing sounding and I haven’t even changed out the stock tubes yet.

When pairing amps and preamps great care just be taken to make sure they are really a good fit. If you stick with all Rogue it’s meant to be used together taking component matching issues out of play.

Having said all that, I’ve read great things about Bel Canto but have little experience myself.

Thanks everyone for great feedback.  I’m going to do my best to do a home audition of both pieces.  Stay safe, healthy and warm!   

the rogue audio RH 5 tube headphone amp (yes) is the sweet spot in their linestage lineup.  superb transparency and dynamics to die for.  
do not discount the effects and contributiobs of a good preamp.