Note: "A" Date Code: The "A" Date Code ran for 18 months (July 1969 - December 1970) so the "B" Code was not used.
1979-1981: Some Marshalls made from 1979 to 1981 have the serial number on the front panel.
In the early 1960s Jim Marshall was a drum/percussion retailer in Hanwell, London. Fender amps were popular but expensive and Jim thought he could produce them at a better price. The main difference was he used four 12 inch Celestions in a closed back cabinet vs the Bassman’s four 10 inch Jensen speakers with an open back.
After a successful career as a drummer and teacher of drum technique, Jim Marshall first went into business in 1962 with a small shop in Hanwell, London, selling drums, cymbals and drum-related accessories; Marshall himself also gave drum lessons.
This (a)(b)(c) sequence began in 1969 and was valid through 1983.
How to read the serial number (1984-1992) In 1984, the order of the serial number components changed to (a)(c)(b), but the method used to determine the values for (a) and (c) remain the same.
Post a link of the desired amp on the “Ebay Watch Post”, so we can help analyzing it. I’ll concentrate on “how they sound”, “how they look like” and also “how to tell them apart”. It was made as a head and as a combo (known as the “Bluesbreaker” combo).
In this article, I’ll try to cover the more “desirable” Marshall amps that were built since 1962 up to the JCM800 series, wich most consider to be the “last” great Marshalls produced (That until Marshall released the Vintage Modern series. I will also try to give examples of where they were used.. I hope you like it These are just a few of the thousands of codes that Marshall came up with for their amps. There were many cosmetic changes on the first years until it finally got the “Classic Marshall Look” by 1964.
According to Jim, Ritchie Blackmore, Big Jim Sullivan and Pete Townshend were the three main guitarists who often came into the shop and pushed Marshall to make guitar amplifiers and told him the sound and design they wanted. then expanded, hired designers and started making guitar amplifiers to compete with existing amplifiers, the most notable of which at the time were the Fender amplifiers imported from America.
These were very popular with guitarists and bass players, but were very expensive.
Marshall amps began featuring aluminum back panels in 1969.
Serial numbers began appearing on the back panels in July 1969.
This is the reason why Marshalls of this early era (up to 1968) are known as “Plexis”.
The sound of this amplifier is “creamy” and “warm”. This amp is more suited for blues players, with a smoother sound.