Marshall Master Reverb 30 5203 preset

Verified · 90/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The 5203 Master Reverb 30 is a 30-watt solid-state combo from Marshall's 1980s transistor range, sold alongside the valve JCM800 line as a practice and small-gig amp. A single input feeds op-amp gain stages with an LED clipping pair, then Treble, Middle, Bass, Presence and Master Volume, plus spring reverb with its own level. A complementary MJ3001/MJ2501 output pair drives a 4-ohm speaker, with headphone and direct outputs.

• Made in: UK
• Wattage: 30W
• Channels: 1

Tags: british, solid-state, reverb, mid-wattage, practice.

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.