Gibson GA-45 Maestro - Normal preset

Verified · 86/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The GA-45 Maestro is a Gibson-built tube amp sold under the Maestro name, designed for accordion as well as guitar. Two 5879 pentode input channels feed a 12AX7 paraphase inverter and a pair of 6V6GTs. A 6SQ7 tremolo with remote switch is fitted, and the amp drives four speakers. The pentode front end and 6V6 output give a warm, low-powered tone that breaks up early.

• Made in: USA
• Wattage: 16W
• Channels: 2
• Preamp tubes: 2× 5879, 1× 6SQ7, 1× 12AX7
• Power tubes: 2× 6V6GT

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

Schematic-derived preset files for the Neural DSP Quad Cortex and 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.