What tubes does the Marshall JMP-1 Preamp - OD 2 use?

The Marshall JMP-1 Preamp - OD 2 uses 4× ECC83 preamp tubes and — power tubes.

When was the Marshall JMP-1 Preamp - OD 2 produced?

The Marshall JMP-1 Preamp - OD 2 was produced 1992–2000.

Marshall JMP-1 Preamp - OD 2 preset

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

The Marshall JMP-1 is a MIDI-programmable rackmount tube preamp introduced in the early 1990s, delivering up to 100 fully programmable presets from a compact 1U chassis. Its four independent channels — two clean and two lead — and integration with the 9005/8008 power amps made it the definitive Marshall rack solution.

Years produced: 1992–2000
Made in: UK
Channels: 4
Preamp tubes: 4× ECC83
Power tubes: —

Tags: rackmount, preamp, midi, british.

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.