Music Man GP-3 preset

Verified · 87/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The GP-3 is a single-channel Music Man guitar amp built in 65 W and 100 W versions. Its LM1458 op-amp preamp has hi/lo inputs, bright and deep switches, a three-band EQ and a footswitchable gain path with a limiter. It adds spring reverb and a four-stage optical phaser, and transistor drivers feed two 6CA7/EL34 output tubes.

• Made in: USA
• Wattage: 100W
• Channels: 1
• Power tubes: 2× 6CA7

Tags: american, vintage, hybrid, clean, reverb, el34.

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.