Marshall JTM45

Marshall sought the advice of his shop repairman Ken Bran, who recommended electronics "whiz kid" Dudley Craven as the chief circuit designer.

As Bran later said, "The JTM also had different harmonic content, and this was due to the large amount of feedback that Dudley Craven had given it.

The first-ever use of this JTM 45 model in a live performance was in September 1963, when the amplifier was tested at the Ealing Club, a short distance from the original Marshall shops.

[8] Production of this model ceased in 1966, but it was reissued in 1989, albeit with a modern printed circuit board and 6L6 output valves.

[5] In 2014 Marshall reissued a "handwired" 30 W amplifier based on the JTM45, the 2245THW, whose circuitry is identical to the 1962 combo circuit; it is a "fine high-end piece" according to Vintage Guitar, listed at $4,800.