It's been many years since I've had the v, but I can help with some of this: W.r.t. Your beyers, what's the sensitivy on them? Because the Val is made for high impendance dynamics and the power drops sharply as the transducer impendance goes down, peak is 800mw at 300 but drops to only 180mw at 50. Those beyers might just be too low impendance for it. gold pins don't really matter, except that you don't need to clean the pins of you leave them in a box for years and they oxidize a bit. iirc the input tubes matter more than the output tubes, sound wise. pair matching won't hurt, and any tube so rare that getting a matched pair is too expensive is too expensive to put in this amp. Not sure what's considered the best cheap tube for them now, but a pair of GE JAN 5670w with adapters for 6922, with all the trimmings, triode & pair matched, are 50 bucks from tubedepot.