Gibson GA-40T Crestline - Channel II preset

Verified · 91/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The GA-40T Crestline is a two-channel 1960s Gibson combo, two inputs per channel, with a volume control on each channel and a shared tone control. Its tremolo is a 12AU7/6EU7 oscillator flashing a bulb onto a photocell (LDR), with frequency and depth controls and a footswitch. A 6EU7 phase inverter drives a fixed-bias push-pull pair of 7591 output tubes on a GZ34 rectifier into a 12-inch speaker.

• Made in: USA
• Wattage: 30W
• Channels: 2
• Preamp tubes: 3× 6EU7, 1× 12AU7
• Power tubes: 2× 7591

Tags: american, vintage, clean, tremolo, two-channel.

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.