Marshall amplifiers made hard rock possible. While Fender and Vox amps have their place in moving electrified guitar forward, the creations of Jim Marshall fostered an entirely new sound and allowed guitarists to fill stadiums with it. Marshall amps had such precedent-setting wattage and tone that their history can hardly be separated from the history of rock itself.

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. The guide below will help you quickly and clearly date Marshall amps and cabinets, without us waxing poetic about their influence.

Click here to skip directly to information on Marshall serial numbers.

Before we begin, a few caveats:

  • Marshall model numbers look like years. If your amp says Model 1986 on the inside, that does not mean it was made in 1986. This is probably the biggest area of confusion when dating Marshall amps.

  • True serial numbers weren't really used by Marshall until July 1969, so specimens made prior to that can only be accurately dated to a fuzzy span of several years.

  • All Marshall amps originally came with Celestion speakers, so in cases where the speakers are original, speaker date codes can be used to date earlier amps.

  • Marshall cabinets didn't officially include serial numbers until October 1992. As a result, dating cabs can be more art than science.

The best approach is to cross-reference the serial number with known features for the model during different eras and the personal account of previous owners. Getting the correct year is one thing, but getting the story behind an amp is the fun part. The guide for that is much simpler: be nice, ask questions, offer beer.

Marshall Amps By Series

If you have absolutely no idea whether your Marshall is old or new, a good place to start is the model name or series. This will give you an approximate idea of the era during which your amp was manufactured. It's also one more piece of evidence to pair with the serial number to corroborate the actual year.

The first Marshall amps were made in England starting in 1962. Production has continued there uninterrupted through today, though some lower-priced models are now made in China, India or Korea, depending on the series.

JTM-45 Models: 1962 - 1966
Bluesbreaker Combos: 1964 - 1972
Four-Digit Models (no series): 1965 - 1981
JCM 600 Series: 1997 - 1999
JCM 800 Series: 1981 - 1991
JCM 900 Series: 1990 - 1998
JCM 2000 Series: 1998 - 2008
Silver Jubilee Series: 1987 - 1989
30th Anniversary Series: 1992 - 1999
JTM Series: 1995 - 1998
35th Anniversary Series: 1997 only
Solid State 5000 Series: 1984 - 1991

Valvestate Series: 1991 - 2000
AVT Series: 2000 - 2007
Mode Four Series: 2003 - 2008
MB Series: 2006 - 2012
Hand-Wired Reissue Series: 2004 - present
JVM Series: 2007 - present
Vintage Modern Series: 2007 - present
Haze Series: 2009 - present
MA Series: 2009 - present
MG Series: 1999 - present
JDM:1 Series: 2010 - present

Some amps won't fit into these series (like the recent Class 5 Combo or various signature and limited edition models), so using the serial number will be your best bet to hone in on a specific date of manufacture.

Marshall Serial Numbers

To find the serial number on your Marshall amp, start by looking at the back panel of your amp. For models made between 1979 - 1981, the serial number will be on the front panel.

Keep in mind that no reliable serial number information exists for pre-1969 Marshall amps, so if your amp doesn't have a number matching one of the formats below, it is likely pre-1969 and identifiable by features rather than serial number.

Click on the links here to jump directly to the serial number style that matches your instrument:

Early Models: 1962 - 1964

The earliest Marshall amp models did not have model codes or any official serialization, though some models had a simple sequential four-digit numbering system inside the back panel. These numbers supposedly started with 1001 and progressed from there, starting with 2001 at the beginning of 1964. Often these specimens produced between October 1962 and December 1964 had an offset chassis. Look for original black levant covering, a gray grille and the old block-style Marshall logo.

Model Codes Without Serial Numbers: 1965 - 1969

From January 1965 to June 1969, model codes were used but no known serial numbers accompanied them. This era saw the advent of Plexiglas panels (giving rise to the "Plexi" name) and four-digit model numbers. Amps from this era still have the block-style Marshall logo and a centered chassis.

The model codes below should help you identify which model you have, while the characteristics described for each year should help with dating.

S/ 50W
/A 200W
SL/ 100W Super Lead
SB/ 100W Super Bass
SP/ Super PA
T/ 50W Tremolo
ST/ 100W Tremolo

1965 Features

  • Cream back panels
  • JTM-45 block logos changed to gold-plated plastic script (these are rarely original, as they broke easily)
  • Small round gray cabinet feet
  • Plastic handles with larger ends compared to earlier models
  • KT66, 6L6 and 5881 tubes in the power section
  • RS Spares or Drake transformer used in the JTM-45 (the Drake rated at 8000 ohms)
  • Some JTM-100 amps appear with the JMT-45 badge in late 1965 (check for two 50W transformers and a solid state rectifier)

1966 Features

  • EL34 or 6550 tubes in the power section
  • JTM-50 and JTM-100 logos debut, indicating the amp's wattage.
  • Single 100W Drake transformer for 100W models (rated at 4000 ohms)
  • GZ34 rectifier no longer used
  • Corner-lock joints on cabinets with a quality control signature inside

1967 Features

  • Reverse JTM logo (aka "Black Flag") used for half the year, carrying over from late '66
  • Gold Plexigas back panel (as opposed to cream-colored)
  • Dagnall transformers used in the JTM-100 (replacing the Drake)
  • Chassis construction transitions from aluminum to steel in late '67

1968 Features

  • White logo (as opposed to gold)
  • Amp model prefix changed from JTM to JMP (Jim Marshall Products)
  • Transformer turned 90 degrees in comparison to earlier models (to reduce hum)
  • Curved lip under the control panel (previously straight lip)

1969 Features

  • Larger black cabinet feet circa July '69 (earlier feet were small and gray)

Model Code-Serial-Date Code: 1969 - 1983

Starting in July 1969, Marshall starting using official serial codes. They were initially broken down into three parts: the model code, the serial production number and the date code. Marshall used letters as a date code to represent year of production. It's important to note that, prior to 1984, this letter came last. The letter B was skipped, as were the letters I, O and Q since they might be confused for numbers.

Use the model codes and date codes below to determine the model and age of your amp. For example, the number S/A 8481 E tells us that this is 50W amp (S/A) made in 1973 (E), production number 8481.

Model Codes

S/ or S/A 50W
SL/ or SL/A 100W Super Lead
SB/ or SB/A 100W Super Bass
A/ or /A 200W
T/ or T/A 50 W Tremolo
ST/ or ST/A 100W Tremolo
SP/ Super PA