Contrary to what is written in another post, I'm not sure that there is a version in two 12-inch speakers (there would be no place to put them, in my opinion).
However, there are indeed two versions, the JTM30-312 with a Celestion G12 Heritage and JTM30 version with two HP 10pouces (not 12) mounted most often with Eminence Heritage 10.
And in my opinion, that is only my opinion, only the amplifier section is interesting, and they had the good sense to an outside cabin output 16ohms rear

USE

And in my opinion, that is only my opinion, only the amplifier section is interesting, and they had the good sense to an outside cabin output 16ohms rear

SOUNDS

And in my opinion, that is only my opinion, only the amplifier section is interesting, and they had the good sense to an outside cabin output 16ohms rear

NOTICE GLOBAL

And in my opinion, that is only my opinion, only the amplifier section is interesting, and they had the good sense to an outside cabin output 16ohms rear