Need recommendation for amplifier

rvpiano
 I know your Red Dragon recommendation was well intended but
 he failed to look at the big picture.
Your tube preamp has a high output impedance
 the Dragons have a 10 k input impedance.
This will be a pretty bleak match.
 I would suggest you look at the Belles Aria Mono Blocks with a 100 k input impedance tube Pre amp friendly and plenty of current to work with the Dahlquist DQ 20s and many other fine speakers.
Here is a review of the Aria Integrated FYI the mono versions of these amps are a real wonderful performer, made in USA and I think you will find even more sophisticated then what you are already enjoying.
http://www.powermodules.com/ewExternalFiles/HFC_412_Exotica_Belles_Reprint.pdf
 Best,
 JohnnyR
Audio Connection

500 ohms is high? That seems low enough to me!
https://www.stereophile.com/content/conrad-johnson-pv11-preamplifier-specifications

JohnnyR,

The Belles Aria monoblocks are a little out of my price range,
 Thanks for the recommendation though.

+1 for Odyssey Audio amps. Also, I would audition Merrill Taranis and Arion Audio S-250. Both are great amps.

@cscrutinizer Take another look at Rogue.  A Cronus Magnum II knocked my Ayre AX-7 off its perch.  And if you have the $$, RP-5 + Stereo 100.