Swapping valves

I don't know whats in at the moment? They are unbranded although taking into account the kt88's are top svetlanas I can't imagine the 5U4G rectifier is of poor quality. The input valves are RCA 6SH7 which I haven't seen any other brand of.

 

EH should be better, although they may be svets anyway- EH don't manufacture tubes, they buy up what ever is around and sort the cream of the crop. The EH branded 12ax7's are Sovtek for example. Not sure what the KTs are though.

 

It's interesting how tube rolling varies. With 6 x EL34 I replaced EH with Winged C Svets, sophisticated being the best word for the Svets compared with agricultural for the EH. As you say Anex, it's a bit of a lottery with EH.

Agree wholeheartedly that driver valves are the biggest difference. I've done this with 834P Deluxe ECC83s, Unison S6 ECC82s and First Audio Monoblocks 6922/E88CCs. There's little point posting specifics as tubes vary so much from sample to sample or amp to amp. Definitely worth playing with though.

Paul