Check out how all changes between 1967 and 1974 affected tone on the Plexi / Metal Panel Superlead amp.

Roe Fremstedal:
The Evolution of the 100W Circuit: From JTMs to JMP Superleadshttp://folk.ntnu.no/roef/JTM100.html

Clay Finley: Marshall Circuits 101
http://www.amparchives.com/Amp%20Arch...