Marshall JCM800 2203 preset

Verified · 85/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The JCM800 2203 is the 100-watt single-channel master-volume head, successor to the 1975 JMP 2203. Cascaded ECC83 gain stages and a master volume after the tone stack let the preamp overdrive while four EL34s stay at usable volume. Its aggressive midrange became a reference for 1980s hard rock and metal, and Marshall later issued signature versions for Zakk Wylde and Kerry King.

• Years produced: 1981–1990
• Made in: UK
• Wattage: 100W
• Channels: 1
• Preamp tubes: 3× ECC83
• Power tubes: 4× EL34

Known for: Zakk Wylde, Kerry King, Billy Corgan, Jeff Hanneman.

Heard on: No More Tears — Ozzy Osbourne (1991); Cherub Rock — The Smashing Pumpkins (1993).

Tags: british, crunch, high-gain, metal, el34, high-wattage.

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.