Marshall J410-60-00-00-S printed circuit board

Marshall J410-60-00-00-S printed circuit board. PWR-AMP PCB H/LOAD PANEL ASSEMBLY. From guitar amplifier, 2017. Fitted with Marshall EL34 valves (x4), and Marshall ECC83 valves (x5)

Marshall is an iconic British company that has been building highly regarded guitar amplifiers and speakers since 1962, when Jim Marshall began producing amplifiers to meet the demand for loud rock and roll guitar. The Marshall logo is familiar to many people who have seen it on stage behind their favourite performers.

This circuit board illustrates several aspects of the production process of Marshall amplifiers. The board is marked with the names of the people who built, wired and tested it in the factory – a practice introduced by Jim Marshall to facilitate quality control, and to encourage workers to take personal pride in their own work. The names on these boards are mostly women, who have, from the very first production line in the 1960s, been responsible for the detailed work of hand-wiring the boards.

The board is fitted with the valves that power the amplifier. Thermionic valves like these are near ubiquitous in media technologies from the first half of the 20th century and would have been found in almost every home, but they were largely superseded by transistors from the 1950s onwards. Today, domestic valve-based devices are rare, but the Marshall amplifier demonstrates that there remains a niche but active market for this technology, as valve amplifiers are highly valued by many guitarists.