The Marshall JTM45 was the first amplifier ever produced by Marshall as Jim Marshall looked for a cheaper alternative to the Fender Bassman.  While the circuit is basically the same as the Bassman, the most noticeable difference is that the speakers are housed in a closed back cabinet, while the Bassman speakers were housed in an open back cabinet.

There is little documentation available on the Marshall JTM45 and what little we could find comes as “officially” as one can get, straight from Marshallamps.com, the official website for Marshall amplifiers.

Models produced in the 1962 feature a smooth black covering with a white grill cloth, leather handle, and silver polished aluminum panels. The rectangular metal logo has red block lettering. Single speaker output was made with either 5881 or 6L6 valves. Cabinets housed Celestion G12 15 speakers and it is believed that serial numbers start at 1004.

1963 models are similiar, with twin speaker outputs, Black knobs, and white engraved panels. The cabinets also are angled as opposed to straight.  In 1964 the valves used wer KT66’s and the g12 15’s were replaced with G12 20’s. Serial numbers begin with the number 2, and some may have gold and black plastic logos. Marshall also started introducing combos in 1964.

In 1965 identifying models and changes to the original amp becomes hazy for everyone, including the company. It was the year the elusive Marshall Bluesbreaker amps (sometimes referred to as JTM45’s super tremelo) were produced.

Marshall JTM45’s are difficult to find and identify, mostly due to poor record keeping by the company as they first got started. However, it is an amp that made history and began the success of one of the most well known and popular amplifier manufacturers today.

But enough confusing history, let’s hear some music!

If you’d like to get your hands on a Marshall JTM45, you might be able to find one on ebay:

Do you own a Marshall JTM45 amp? Share your thoughts on it (or any missing pieces of the history puzzle) below!