Marshall Jmp 1 preset

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

The Marshall JMP-1 refers to the original JMP Super Lead 100-watt head introduced in 1966, the amplifier that established the template for all subsequent Marshall designs and effectively defined the sound of British rock. Derived from Jim Marshall's heavily modified Fender Bassman circuit with additional gain stages and a characteristically voiced EQ network, the JMP Super Lead's four-input, four-EL34 design became the standard for rock amplification worldwide. When driven to saturation by loud playing or boosted input signals, it produces the massive, harmonically complex roar heard on countless defining rock recordings.

• Years produced: 1966–1981
• Made in: UK
• Wattage: 100W
• Channels: 1
• Preamp tubes: 3× ECC83 (12AX7)
• Power tubes: 4× EL34

Known for: Jimi Hendrix, Jimmy Page, Pete Townshend, Eric Clapton.

Heard on: All Along the Watchtower — Jimi Hendrix (1968); Whole Lotta Love — Led Zeppelin (1969).

Tags: british, vintage, crunch.

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.