Gibson GA-100 Bass preset

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

The GA-100 is a 1960s Gibson bass amplifier. A 6EU7 input stage and treble/bass network feed a 6EU7 cathodyne and 6BD6 pentode drivers into a pair of fixed-bias 6L6GC tubes. A 6FM8-based compressor with its own switch and a GZ34 rectifier complete it.

• Made in: USA
• Wattage: 60W
• Channels: 1
• Preamp tubes: 1× 6EU7, 2× 6BD6, 2× 6FM8
• Power tubes: 2× 6L6GC

Tags: american, vintage, bass, 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.