Gibson GA-20T Ranger preset

Verified · 80/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The GA-20T Ranger is the tremolo version of the GA-20, a single-channel Gibson combo of the late 1950s. Two inputs feed a 12AY7 with one volume and one tone control, a 12AX7 splits phase for a push-pull pair of 6V6GT tubes on a 5Y3GT rectifier, and a valve tremolo built around a 5879 phase-shift oscillator and a 6SQ7 adds depth and rate controls with a remote footswitch jack. One 12-inch speaker.

• Made in: USA
• Wattage: 14W
• Channels: 1
• Preamp tubes: 1× 12AY7, 1× 12AX7, 1× 5879, 1× 6SQ7
• Power tubes: 2× 6V6GT

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

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.