What tubes does the Marshall Jmp Bass 50W 1986 use?

The Marshall Jmp Bass 50W 1986 uses 4× ECC83 preamp tubes and 2× EL34 power tubes.

When was the Marshall Jmp Bass 50W 1986 produced?

The Marshall Jmp Bass 50W 1986 was produced 1965–1981.

Marshall Jmp Bass 50W 1986 preset

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

The Marshall 1986 is a 50W bass head built on the JMP plexi circuit, the bass counterpart to the 1987 guitar head. Its high headroom and musical EQ response attracted guitar players as well as bassists, and it has been repurposed as a guitar amp by many players.

Years produced: 1965–1981
Made in: UK
Wattage: 50W
Channels: 2
Preamp tubes: 4× ECC83
Power tubes: 2× EL34

Tags: british, vintage, bass, plexi.

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.