Fender Twin Reverb AB763 preset

Verified · 92/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The AB763 Twin Reverb is the blackface Twin, a 2×12 combo with Normal and Vibrato channels, each with two inputs, volume, treble, middle, bass and a bright switch. Spring reverb and optical vibrato with speed and intensity sit on the Vibrato channel, both pedal-switchable. A 12AT7 inverter drives four fixed-bias 6L6GCs from a silicon rectifier. It has huge headroom and a bright, clear clean tone, and it is the standard loud clean amp for country, jazz, funk and pedal-based rigs.

• Years produced: 1963–1967
• Made in: USA
• Wattage: 85W
• Channels: 2
• Preamp tubes: 4× 12AX7, 2× 12AT7
• Power tubes: 4× 6L6GC

Known for: Mike Bloomfield, Eric Johnson.

Heard on: How Soon Is Now? — The Smiths (1984).

Tags: american, vintage, blackface, reverb, vibrato, 6l6, high-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.