Marshall JMP Super Bass 100W 1992 - Normal preset

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

The Marshall 1992 Super Bass 100W is the definitive Marshall bass amplifier of the JMP era and one of the most influential bass amp designs ever produced. Its four-input, two-channel layout mirrors the Super Lead, but the voicing rolls off high-frequency harshness and adds low-end extension to support bass guitar fundamentals at full volume. John Entwistle of The Who and Lemmy Kilmister of Motörhead are among its most famous users, and its ability to produce enormous clean headroom while still delivering presence and midrange cut set a standard that few bass amplifiers have equalled.

• Years produced: 1966–1981
• Made in: UK
• Wattage: 100W
• Channels: 2
• Preamp tubes: 3× ECC83 (12AX7)
• Power tubes: 4× EL34

Known for: John Entwistle, Lemmy Kilmister, Cliff Williams.

Heard on: My Generation — The Who (1965); Overkill — Motörhead (1979).

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.