DIY Pee Wee Hammond (AO-44 Conversion) preset

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

The Pee Wee Hammond is a 2013 DIY conversion of a Hammond AO-44 organ amp into a guitar amp. A Fender AB763 normal-channel preamp on a 12AX7 (treble, bass, volume and bright switch) was added in front of the stock AO-44 power amp, whose ECL86 triode-pentodes provide a gain stage, a split-load inverter and a cathode-biased push-pull output, with an EZ81 rectifier. The result is a small, low-powered amp with a blackface-style front end.

Tags: diy, low-wattage, 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.