Marshall JCM900 Dual Reverb 100W 4100 - Lead preset

Verified · 87/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Marshall JCM900 Dual Reverb 4100 is the sound of 1990s rock in a box — every grunge stage, every alternative club, every Seattle rehearsal space ran one of these. Two channels, built-in reverb, 100 watts of EL34 output, and a diode-clipping preamp stage that pushed the gain further than any previous Marshall production amp. The controversy surrounding that diode clipping never dimmed its commercial success: Pearl Jam's Stone Gossard and Mike McCready played them live throughout the Ten era; Kurt Cobain used them; Kim Thayil relied on them for Soundgarden's massive guitar sounds; Kirk Hammett tracked rhythm parts through them. The JCM900's compressed, aggressive midrange and slightly compressed low end sit in a rock mix in a way that the cleaner JCM800 does not — which is precisely why it defined a decade.

Known for: Stone Gossard (Pearl Jam), Mike McCready (Pearl Jam), Kurt Cobain, Kim Thayil (Soundgarden), Kirk Hammett (Metallica).

Heard on: Alive — Pearl Jam (1991); Even Flow — Pearl Jam (1991); Black Hole Sun — Soundgarden (1994).

Tags: british, crunch, high-gain.

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.