Gibson GA-8 (6V6) preset

Verified · 88/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

This GA-8 is a small single-channel 1950s Gibson amp with two inputs, a volume control and a tone control. Both halves of a 12AX7 provide the gain, driving a pair of 6V6GT output tubes with no separate phase-inverter valve: the second 6V6 takes its drive from a tap on the first tube's screen circuit, a self-splitting arrangement. The pair is cathode-biased, with a 5Y3 rectifier and a single speaker.

• Made in: USA
• Wattage: 9W
• Channels: 1
• Preamp tubes: 1× 12AX7
• Power tubes: 2× 6V6GT

Tags: american, vintage, clean, 6v6, low-wattage.

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.