Marshall started using their four-digit model system around this time and most models should have this on the chassis.Amps from this era are covered in black levant with a black front on heads or gray grille on combos, feature an old block-style Marshall logo, and all chassis' are mounted center.
The charts are listed for the model and date codes, and the serial number is simply the production ranking.
These serial numbers are on the back of the chassis, except for the years 1979-1981 when they were on the front panel.
Dating Marshall amplifiers can be challenging, but most information is available to correctly identify the date.
In 1969, Marshall started using both model codes and serial numbers, which are listed here.
Up until 1983, the order is model code, serial number, then date code.
In 1984, it changed to model code, date code, and serial number. Examples: SL/A G 10058 is a 100W Super Lead produced in 1975.
August 1997-Present - Marshall expanded on their previous idea with a bar code and added more information to the serial number.
This new number contains two letters and 10 digits, wihch is applied to all amps and speaker cabinets.
Examples: M-19-B indicates an amp built in the England production facility in the 34th week of 1999, is serial number 1234, and the voltage is set for U. Blue Book of Acoustic Guitar Values Online Subscription This online subscription contains the entire database of the current Blue Book of Acoustic Guitars, but it also has many features not available with the printed version, including quarterly updates, complete search abilities, and inventory capabilities through Gear Tracker!
Blue Book of Electric Guitar Values Online Subscription The Blue Book of Electric Guitars is available as a stand-alone online subscription in 24-hour, one-year, two-year, or three-year durations, as part of the Blue Book of Acoustic & Electric Guitars online subscription in 24-hour, one-year, two-year, or three-year durations.
We recently wrote an article detailing that rich history (which you can read here), but for those simply looking to figure out how old their Marshall amp is, we offer this shortcut.