Marshall

JMP 1987

50W Handwired Small Box Head – 1973

Serial Number: S/A 1769E
Inspection Sticker Date: 06/02/1973 – 6th February 1973

A superb example of a 1973 Marshall JMP 50 Lead Model 1987 Small Box head, presented in very good original cosmetic condition and retaining its desirable original Drake transformers.

Dating from Marshall's highly regarded early-'70s period, this handwired 50-watt amplifier delivers everything you'd expect from a great vintage JMP — rich harmonics, aggressive British crunch, warm midrange and exceptional dynamic response.

The small box headshell is a particularly attractive feature of these earlier 50-watt Marshalls, offering the classic proportions and styling associated with some of the most sought-after amplifiers of the era.

This example retains much of its original circuitry, including period components and solder joints, while benefiting from a recent comprehensive professional service.

Chassis & Originality

• Original Drake 1202-118 laydown mains transformer

• Original Drake 784-139 output transformer

• Handwired turret-board construction

• Original factory inspection sticker dated 6th February 1973

• Original Bulgin mains connection upgraded to a modern IEC input

The amplifier has been carefully maintained with attention to preserving its vintage character while addressing necessary electrical and reliability considerations.

Professionally Serviced

Freshly serviced on 15th October 2026 by Dave Wittering of Prestige Amp Servicing, former Marshall senior service engineer.

Work carried out includes:

• V1 and phase inverter anode load resistors replaced

• Dedicated chassis earth fitted for electrical safety

• All six potentiometers replaced

• All six input and output sockets replaced

• New OEM Marshall ECC83 fitted in V1

• Full professional inspection and operational testing

The amplifier is in excellent working order, fully serviced and ready to use.

Valves

Preamp: ECC83 / 12AX7, including a new OEM Marshall ECC83 in V1.

Power Valves: Matched pair of Russian-made Tung-Sol EL34B output valves.

The classic EL34 output stage gives the Model 1987 its unmistakable response, combining a powerful midrange with wonderfully musical compression as the amplifier is pushed.

Cosmetic Condition

The amplifier is in very good condition for its age, retaining its original:

• Small box headshell

• Black tolex covering

• Marshall script logo

• Carrying handle

There are some minor signs of age and use, but overall this is a very well-preserved example of an early-'70s Marshall.

Classic JMP 50 Tone

The Model 1987 is one of Marshall's most celebrated amplifier circuits, offering much of the authority and punch of the 100-watt Super Lead but with a slightly sweeter response and earlier power-stage breakup.

Its traditional four-input, two-channel arrangement allows the brighter Lead channel to be combined with the warmer Normal channel, providing a surprisingly broad range of tones.

From bold, articulate cleans through to thick, harmonically rich overdrive, the JMP 50 remains exceptionally responsive to playing dynamics and guitar volume changes.

A fantastic vintage Marshall for anyone looking for the authentic sound and feel of a handwired, non-master-volume amplifier from the early 1970s.

Worldwide Shipping Available

All of our amplifier heads are shipped in custom-made Overdrive Guitars boxes, with additional internal protection to ensure they arrive safely.

We generally use UPS for international shipments and have extensive experience shipping vintage Marshall amplifiers worldwide, with regular deliveries to North America and Europe.

We are proud to be an Authorised Marshall Retailer, offering new Marshall equipment alongside our carefully selected collection of vintage and pre-owned amplifiers.

Our dedicated West London showroom is available by appointment, where customers are welcome to view, test and experience our amplifiers in person.