What tubes does the Marshall JMP 2203 (6550) use?

The Marshall JMP 2203 (6550) uses 3× ECC83 preamp tubes and 4× 6550 power tubes.

When was the Marshall JMP 2203 (6550) produced?

The Marshall JMP 2203 (6550) was produced 1975–1981.

Marshall JMP 2203 (6550) preset

Verified · 87/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The JMP 2203 is Marshall's first 100-watt master-volume head, introduced in 1975; this is the 1976 US-market version. High and Low sensitivity inputs feed cascaded ECC83 gain stages with a preamp Volume, and a cathode follower drives Treble, Middle and Bass, with the Master after the tone stack so the preamp can overdrive at lower volume. An ECC83 inverter with Presence drives four 6550s. It is the direct ancestor of the JCM800 2203.

Years produced: 1975–1981
Made in: UK
Wattage: 100W
Channels: 1
Preamp tubes: 3× ECC83
Power tubes: 4× 6550

Tags: british, vintage, crunch, high-gain, el34, high-wattage.

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.