Fender Pro Reverb AB668 - Vibrato preset

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

The AB668 is the 1968 Pro Reverb from the switch between blackface and silverface. It is a 2×12 combo with Normal and Vibrato channels, tube-driven reverb and vibrato, and a pair of 6L6GCs on a GZ34 rectifier for about 40 watts. It stays close to the blackface design.

• Made in: USA
• Wattage: 40W
• Channels: 2
• Preamp tubes: 3× 7025, 1× 12AX7, 2× 12AT7
• Power tubes: 2× 6L6GC

Known for: Guy King.

Tags: american, vintage, silverface, reverb, vibrato, 6l6, 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.