Fender Vibro Champ AB764 preset

Verified · 89/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The AB764 Vibro Champ is the Champ with vibrato: a 12AX7 preamp with bass and treble, a second 12AX7 vibrato oscillator, and a single-ended 6V6GT on a 5Y3GT rectifier for about 5 watts. The circuit was used in late blackface and silverface models and breaks up sweetly at low volume.

• Made in: USA
• Wattage: 5W
• Channels: 1
• Preamp tubes: 2× 12AX7
• Power tubes: 1× 6V6GT

Tags: american, vintage, vibrato, 6v6, class-a, 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.