Fender Bassman AC568 - Bass Instrument preset

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

The AC568 is the 1968 Bassman head from the switch between blackface and silverface. A Bass Instrument channel with a Deep switch and a blackface-style Normal channel are mixed into another 7025 gain stage. A 12AT7 long-tail phase inverter then drives two fixed-bias 6L6GCs on a silicon rectifier for about 50 watts.

• Years produced: 1968
• Made in: USA
• Wattage: 50W
• Channels: 2
• Preamp tubes: 3× 7025, 1× 12AT7
• Power tubes: 2× 6L6GC

Tags: american, vintage, silverface, bass, 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.