Marshall Jcm800 Artist 30W 4203 preset

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

The Marshall JCM800 Artist 4203 is a 30-watt combo variant of the JCM800 series aimed at players who wanted genuine JCM800 tube tone at more moderate power levels. The Artist designation within the JCM800 series indicated a slightly refined voicing with emphasis on musical dynamics over sheer volume, and the 30-watt output stage offers a natural warmth and compression that the more powerful models only achieve at potentially ear-damaging levels. It is a rarer and often overlooked model within the celebrated JCM800 family.

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.