Gibson GA-55V - Microphone preset

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

The GA-55V is the vibrato version of Gibson's 1950s GA-55. It has separate 12AY7 instrument and microphone channels, a 6SC7 paraphase inverter and a push-pull pair of 6L6GAs with a 5V4G rectifier, for 30 watts. Its true pitch-shifting vibrato circuit, built on 6SL7/6SN7/6J5 tubes, is rare among amps of its time.

• Made in: USA
• Wattage: 30W
• Channels: 2
• Preamp tubes: 2× 12AY7, 1× 6SC7, 1× 6SL7, 1× 6SN7, 1× 6J5
• Power tubes: 2× 6L6GA

Tags: american, vintage, 6l6, vibrato, two-channel, mid-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.