Fender Harvard 6G10 preset

verified · 93/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The 6G10 is the final Harvard circuit from the early 1960s, and by this point it is essentially a Champ-style amp: two inputs feed a 12AX7 gain stage, then one Volume and one Tone control and the second half of the 12AX7, which drives a single cathode-biased 6V6GT in class A. There is no phase inverter; 22k negative feedback runs from the speaker, and a 5Y3GT rectifier supplies the high voltage. It breaks up sweetly at modest volume.

• Made in: USA
• Channels: 1
• Preamp tubes: 1× 12AX7
• Power tubes: 1× 6V6GT

Tags: american, vintage, 6v6, low-wattage, breakup.

Schematic-derived preset files for the Neural DSP Quad Cortex and 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.