Marshall Studio 15 4001 preset

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

The Studio 15 (4001) is a single-channel 15-watt valve combo from Marshall's late-1980s range, built for recording and small rooms. One ECC83 triode with a bright-capped Gain control feeds a Treble, Middle and Bass stack and a recovery stage, then an ECC83 long-tail phase inverter with a dual-gang Master Volume after it. Two cathode-biased 6V6s drive the speaker, with a line out, a transformer-balanced DI output and a headphone jack.

• Made in: UK
• Wattage: 15W
• Channels: 1
• Preamp tubes: 2× ECC83
• Power tubes: 2× 6V6

Tags: british, crunch, 6v6, low-wattage.

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.