The output transformers are the critical weak link in tube amps. Better OPTs (larger cores, less induction, better coupling between primary and secondary, less hysterisis distortion and wider bandwidth) equate to better sound quality. BUT - cost goes up! So be prepared to spend more for better OPTs!
I am currently listening to an AN Kits Dac1.1 given to me as a loaner while my dealer upgrades the caps in my AN UK Dac. I think it sounds excellent and I can imagine that you are very happy with the sound you're getting. An upgrade to the output transformers should be a huge upgrade that is the route I would likely pursue. You say you also have a Chord 2qute have you compared it to the ANK?
The event will be held at Acoustic Designs 16074 N. 78th Street, Suite B104, Scottsdale, AZ 85260.
The DACs will be played in an acoustically treated room on a reference system consisting of Focal Maestro Utopia Evos driven by SAE and Acoustic Research gear.
More information here: www.AZAVCLUB.COM