Leslie 21H preset

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

The 21H is a Leslie rotary speaker cabinet for organs, and this is its tube amplifier. It is an organ amp, not a guitar amp. A 6SN7 phase inverter drives four 6V6 tubes in parallel push-pull, powered by twin 5Y3 rectifiers, with a 6J5 controlling the rotor speed.

• Made in: USA
• Channels: 1
• Preamp tubes: 1× 6SN7, 1× 6J5
• Power tubes: 4× 6V6

Tags: american, vintage, 6v6, 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.