Marshall Jcm800 4010 Preamp preset

Verified · 80/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Marshall JCM800 4010 is a 50W 1×12 combo version of the JCM800 series, housing the signature single-channel Master Volume circuit in a portable combo format. It delivers the full JCM800 tone in a grab-and-go package favoured by recording guitarists and club performers.

• Years produced: 1981–1990
• Made in: UK
• Wattage: 50W
• Channels: 1
• Preamp tubes: 4× ECC83
• Power tubes: 2× EL34

Heard on: Welcome to the Jungle — Guns N' Roses (1987); Crazy Train — Ozzy Osbourne (1980).

Tags: british, combo, jcm800, vintage.

Schematic-derived preset files for 16 Fractal and Line 6 modelers: Axe-Fx II/XL/XL+, Axe-Fx III, FM3, FM9, and the full Helix family (Floor, LT, Rack, HX Stomp, HX Stomp XL, Native).

Gridleak extracts amp parameters from original circuit schematics using AI vision — component values, gain staging, tone stack topology, tube types — then generates native preset files for every supported modeler. Every extraction is scored 0–100 and the score is published.