Gibson GA-50 - Instrument preset

Verified · 84/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The GA-50 is an early Gibson combo with two channels: one with a single input and one with three, each built on an octal 6SJ7 pentode with its own volume control. The channels mix into shared treble and bass controls, then a pair of 6J5 triodes forms a paraphase inverter driving a push-pull pair of 6L6GA output tubes on a 5V4G rectifier, with local feedback from the output plates, into two speakers.

• Made in: USA
• Wattage: 25W
• Channels: 2
• Preamp tubes: 2× 6SJ7, 2× 6J5
• Power tubes: 2× 6L6GA

Tags: american, vintage, clean, 6l6.

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.