Psvane KT88 tubes in VAC amps

I've read that small signal tubes takes 50-75 hours of burn-in but if they require 300 hours I'm going to put them back in for another 100 hours and reevaluate.

My observations so far are they have a wonderful midrange but my stock Chinese 12AX7 have more zing and body but we'll see after another 100 hours if that's required.

Listening to them open is at once frustrating and rewarding.
I've yet to identify a sonic signature for the full complement of Psvane's, but I can say at this point that they are very refined. Refined and correct. Maybe that's a function of the whole being greater than the sum of the parts.

ECM live recordings of Schiff's Beethoven cycle are a pretty reliable benchmark for piano sound. But for finesse, try Kissin's version of Glinka's 'The Lark'; the Psvane's handle its upper octaves with breathtaking ease.

Dr_John,

After a few months of burn-in, how's the all-Psvane tube complement sounding in your VAC?

I'm thinking about rolling the 6SN7 tubes in my 300.1a, looking for a little more body and warmth without sacrificing the crystalline clarity of the stock VAC tubes. Suggestions, anyone?

I've retracted my Psvane endorsement as one of my 12Ax7TII tubes failed and made me sad. It will take a while to recover.

i used treasure tubes from shuguang in my vac 450 and did better with the shuguang sc from kevin