12ax7 12AU7 EL34 / KT 88/ 6550 upgrades for PL2

I would get NOS GEC KT88, thats what I did and stop rolling after.

You want punch and musicality at the same time, KT88 are your choice, other than that, EL34 Tesla's are my second one.

Tried:

6550 TUNG SOLS BLACK SMOOTH PLATES, very expensive and I would choose GEC KT88 anytime instead, but they do sound very good and build to last.

EL34 NOS TESLA ( NOT JJ ) - Very good value, recommended.

6550 NOS SYLVANIA - Nothing special, nice sounding.

To me, driving and input tubes make as much difference as the output.

Tried:

12AU7 - Telefunkens Smooth plated, Brimars long plated square getters, Tung Sols Black coated glass and Mullards from the 50's, which I end up with.

12AX7 - Tungsram, Tungsols and CV4004 Mullards, which I ended up with to.

The other one I would recommend is E83CC NOS Tesla, simply one of the best sounding up there. They are identical to E83CC Telefunkens, which are such expensive that these Tesla's are just an bargain. Dont miss up with other E83CC they try to sell, cos only Teles and Teslas are the ones to get, but be carefull with your source choice, cos fakes are there.

I have a prologue 6. The 12AX7's are too good to swap. NOS RCA 12AU7's will upgrade the sound, and I found Tung Sol EL34's to work for me.

Were the 12AX7's that you swapped out, Shuguang. I found them to better than the new tubes I tried.

Orpheus10 - The 12AX7 I swapped were stock primaluna for the cheap EH 12ax7s. I am not sure they are shuguang. Are they? I found the EH 12ax7s to be marginally better but better ... in terms of bass response. Are the NOS RCA 12AU7's clear top?

Yes, they are the best bargain in NOS tubes. I get mine from Brent Jesse. I got my Primaluna new and swapped out the 12AX7's for new tubes but liked the tubes already in better. Call Upscale Audio at 909-931-9686, they can identify which tubes you have.