I can't answer that. It is entirely up to you and your style of playing and your taste. In the real world, the only lower gain tubes that you can find and afford are 12AT7's and 5751 with gain factors of 60 and 70 respectively. You can take certain preamp tubes and get a Marshall sounding too much like a Fender. An example would be putting a 5751 in V1 and V2. The amp would have a cleaner, overall sound. It's not going to crunch as well, because it doesn't have enough "gain" to get crunchy. So what you have is a Fender clean and if you use pedals, well it would work quite nicely. An OD pedal or good distortion box will push those 5751's and then you would get some bite.
That's how some people like to play. Others want as much friggin' gain as possible out of the amp. So is there guys that use 12BZ7's in V1 and V2? You bet there are and I guarantee that their amps are on the verge of taking off like a rocket! If you did any sort of knob cranking, the amp would start to feedback, so you would have to be on stage with a 50 foot guitar cable manipulating the volume to control the thing (or have taken lessons from Ted Nugent). And this is how some people like to play.
I personally like the RCA 7025 (super quiet 12AX7) in V1 with a real solid USA 12AX7(A) in V2 (like a Black Plate with thick mid's). As I've said in prior threads, the signal is going through two tubes, but 4 separate gain stages. I round it up with a couple of sweet Balwin Green Labels made by Raytheon in 1961. Most of the tubes I use are pushing 50 years old. It amazes me that I can still buy them.
Of course you know that in my TSL122 I use a 7025 and three GE's. The GE's have shorter plates and are less prone to microphonics inside of a combo amp. (That's why a 12BZ7 tends to work better in a head instead of a combo. The 12BZ7 has longer plates on it and therefore has a tendency to be microphonic.) I think the GE's sound really good. It's the only amp that I have were I am running three of the exact same tubes in the preamp. I've tried this amp with West German EL34's, but I actually like it loaded with KT77's the best.
So Josh, it's all about your style, how much gain you need and the effects you use. There are guys out there right now that haven't changed their preamp tubes in five years and they think their amp sounds killer. If I was to put a new set of tubes in their amp, they would S**T all over themselves. People are funny that way. Someone can play Hendrix note for note, but not know how to put tubes in his amp (that's what tech's are for).
Anyway, keep experimenting. At least there are three of us (SolarBurn) in on this. Maybe I'll get around to doing some of it myself. However, I would like to do it with currently available tubes, just to see how they hang against the NOS USA tubes.
Marty
