Marshall Jmp Lead 50W 100W preset

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

The JMP Super Lead in both 50W and 100W configurations defined the sound of hard rock and early heavy metal. Built around a four-input, two-channel layout with a shared EQ, the Super Lead's high-sensitivity inputs deliver a raw, mid-forward crunch that cuts through any mix. The 100W version with its quad EL34 power section was famously loud and punishing, while the 50W variant allowed players to push the output stage harder at comparatively manageable stage volumes. Both versions are the backbone of the classic 'plexi' tone.

• Years produced: 1966–1981
• Made in: UK
• Channels: 2
• Preamp tubes: 3× ECC83 (12AX7)
• Power tubes: 4× EL34

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

Heard on: Won't Get Fooled Again — The Who (1971); Whole Lotta Love — Led Zeppelin (1969).

Tags: british, vintage, 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.