Marshall dating serial number
Technology always opens up new avenues for art, and the hundred-watt stacks pioneered by Jim Marshall were no different.
They created not only a new tonal palette, but an entirely new concert experience.
Production ramped up over the course of 1963 with more a standardized centered chassis.
At the time, it was said that Marshall had created the “world’s first great bad amplifier.” Unlike their contemporaries, Marshall amps had distortion coming from the tubes, not the speakers.
The Selmer amps often broke down, so Jim hired a service tech.
That person was Ken Bran, a former Pan Am aircraft engineer and musician.
When Townshend and Entwistle (among others) started asking for amps that could give more than a Fender Bassman (one of the most powerful amps at the time), Bran was the one who opened up a 5F6A Bassman (on loan from employee Mike Borer) and created a schematic from its guts to use as the basis for an entirely new amp.
Marshall amps made it possible to get the sort of stadium-filling, high gain crunch we now associate with rock.The low-wattage speakers of the era meant the amp needed at least four of them, giving rise to the first Marshall cabinet design: closed-back with four 20-watt G12-15 Alnico speakers made by London-based Celestion. Go to any show around town and you’d see plenty of heads and cabinets sporting the metal plate, red block letter Marshall logo.This stood in contrast to the Jensen speakers found in open-backed Fender Bassman 4x10s and added one final element to the Marshall sound. Jimi Hendrix (playing in England in late ‘66), Pete Townshend and John Entwistle were all early adopters.They decided to use this space for branding, adding the name JTM45 and MKII on either side of the switches.This is the more commonly seen iteration of the JTM 45, as it represents the fully realized and standardized version of Marshall’s first amp. Other amps blew up when pushed that hard, but the new Marshalls seemed to enjoy operating at the limit.