OCTAL SUBSTITUTES & GAIN FACTORS...

[ksl]

Hi all~ While i know there are probably NO direct drop-ins for tubes, except for the 12**7 family, and that different rectifiers, if acceptable to the circuit, can change the amp's attitude, albeit not greatly, I am curious about the 6SC,SN,SL,SJ7 family. With appropriate design tweaks, which of these octals share the same pinout or are close enough to be rewired, and could be subbed, if any....?? As I'm legally blind, it's often difficult to easily download & investigate these stats, which is why I come to this place, hoping for some quicker results.
Again, I don't do mods, & all I'm good for is a 3 prong cord, change out an old resistor or cap, install a fuse receptacle, & change tubes. With the octals, I'd like to know what subs are possible, even w/some rewiring, & what their gain factors are....

Basically,  I'm having someone modify some 50/60's mono tube PA amps for guitar use, & was curious to know what tubes that I have in my best collection, can be swapped in for some better gain.

Thank you again, Kenny

[daddymack]

There is a reason why most guitar amp's power sections are designed around  6L6 [5881], 6V6, EL34, EL84, KT66...and there are a number of considerations if you want to change around.

Heater/filament current is a major issue, which is why, for instance,  although a KT66 specs out very close to a 6L6/5881, it isn't directly replaceable. They tend to generate oscillations with the lower current...which can be damped, but is it worth it? Not to me.

Many of the 'old skool' cheapie amps [including early Bogen, Valco, Magnatone] used the 'oddball' radio tubes because they were cheap and plentiful, and very 'forgiving' as far as needing clean ac/dc transformers. You've seen some of those already, and you are now aware of the inherent risks involved with those amps.

I have to say I would go ask over at a different forum, like ampgarage.com...