Leslie Type 25 Booster Amplifier preset

Verified · 90/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Type 25 is a Leslie booster amplifier from the console connector kits used to link organs to Leslie speakers. It is an organ amp, not a guitar amp. A volume control feeds a 12AU7 cathode-coupled phase inverter, with both triodes driving a push-pull pair of 6L6GC output tubes, powered by a solid-state diode rectifier at about 440 volts. It gave consoles without a suitable output enough power to drive a Leslie.

• Made in: USA
• Channels: 1
• Preamp tubes: 1× 12AU7
• Power tubes: 2× 6L6GC

Tags: american, vintage, 6l6, clean.

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.