Marshall Jcm900 21Xx 25Xx 100W preset

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

The JCM900 SL-X 100-watt models (2100 and 2500 series) represent Marshall's high-gain flagship of the early 1990s, offering a single-channel design with substantially more preamp gain than the JCM800 it succeeded. The SL-X circuit uses additional gain stages and a cascaded clipping architecture to achieve the higher saturation levels demanded by the metal and grunge scenes of the era. Despite controversy surrounding the use of diode clipping in the preamp, the SL-X's raw, aggressive character and tight low-end response made it genuinely effective for the music of its time.

Tags: british, 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.