Marshall 1959SLP - Bright preset

Close · 70/100 confidence. Most values readable. Minor gaps filled by inference from similar circuits.

The JCM800 2203 is Marshall's quintessential 80s amp — a 100W single-channel head with a cascaded gain stage that defined the decade's rock and metal tones. Used by Slash, the Cult, and countless others, its aggressive midrange cut became a benchmark for British gain.

• Years produced: 1981–1990
• Made in: UK
• Wattage: 100W
• Channels: 1
• Preamp tubes: 4× ECC83
• Power tubes: 4× EL34

Known for: Slash, The Cult, Dave Murray, Adrian Smith, Gary Moore.

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

Tags: british, crunch, vintage, 80s-rock, metal.

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.