From July 1969 to December 1983, the letter denoting the year was put after the serial number.
The earliest Marshall amplifiers were made in 1962 and had no model or serial numbers.
Many tube amplifiers will have a tube chart within the amp itself.
This may also be helpful when dating a vintage tube guitar amplifier.
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.
This is the reason why Marshalls of this early era (up to 1968) are known as “Plexis”.