Gibson GA-20 (12AY7 Preamp) - Normal preset

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

The Gibson GA-20 with 12AY7 preamp was an early 1950s combo that used the lower-gain 12AY7 tube for a warmer, less distorted clean tone than later 12AX7-equipped versions. This earlier version is prized for its particularly sweet and musical clean character.

• Years produced: 1950–1955
• Made in: US
• Wattage: 14W
• Channels: 2
• Preamp tubes: 1× 12AY7
• Power tubes: 2× 6V6

Tags: american, vintage, 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.