Marshall JTM600 - Clean preset

Verified · 86/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The JTM600 is a 60-watt all-valve two-channel amp from Marshall's mid-1990s JTM range, the design that preceded the JCM600. Relay-switched clean and gain channels, the gain side with diode clipping, each have their own gain, EQ and volume, sharing spring reverb, Presence and both series and parallel effects loops. Four ECC83s cover the preamp and phase inverter, driving two EL34s, with an XLR DI output.

Tags: british, clean, crunch, reverb, mid-wattage, two-channel.

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.