Gibson GA-77RVT Crestline - Channel 1 preset

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

The GA-77RVT Crestline is a two-channel 1960s Gibson combo, two inputs per channel, each channel with its own volume, treble and bass. Channel 2 carries the spring reverb, driven by a 7199 and 12AU7 with its own level control, and a photocell (LDR) tremolo has depth and frequency controls. A 6EU7 long-tail inverter drives a fixed-bias push-pull pair of 6L6GC tubes on a solid-state rectifier into a 15-inch speaker, with a monitor output.

• Made in: USA
• Channels: 2
• Preamp tubes: 4× 6EU7, 1× 7199, 1× 12AU7
• Power tubes: 2× 6L6GC

Tags: american, vintage, clean, reverb, tremolo, 6l6.

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.