NOS 12ax7's in Mesa Boogies

[Octaver]

I just got a bunch of NOS Preamp valves from a Amp Builder friend

 

Some old Telefunkan from 1950's !, Sylvanias, Mullard , GE's

Amperex etc. And some GT Mullard copies

 

Im trying them in my Boogie MKIV

 

I dont know much about the gain structure in these amps,

So far Im just experimenting with the V1 stage .

 

So far there I havent noticed a great difference in the few I have tried

Though the GT's seem to give it more Marshall, Soldano type compression which Im liking.

 

My question is what function *importance* (in gain & tone)

do the V1,V2 & V3 have in this amp & are they as prominent as the V1 ?

[potaetoes]

mark ivs use tubes kinda weirdly. you might try sticking tubes in V2 to affect the R2 channel, and V3 for the lead channel... might give noticeable results, might not. they all share V1, but after that the gain stages are kinda scattered around.

[Octaver]

Interesting I am actually looking to beef up R2 & Lead channel