Marshall JTM310 - Lead preset

Verified · 88/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The JTM310 is the 1x12 combo of Marshall's mid-1990s JTM30, a 30-watt all-valve amp that reused the JTM name on a modern channel-switching design. A Green (clean) channel with its own Volume and a Red channel with Gain and Volume are relay-switched, sharing Treble, Middle, Bass, spring reverb, an effects loop and a Master. Three ECC83s drive a pair of 5881s, with an XLR DI output.

• Made in: UK
• Wattage: 30W
• Channels: 2
• Preamp tubes: 3× ECC83
• Power tubes: 2× 5881

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.