Ampeg Rocket II GS-12 preset

Verified · 89/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Ampeg Rocket II GS-12 is a single-channel tube guitar combo of the mid-1960s. Two inputs feed half a 12AX7, then passive treble and bass and a volume control; the other half of the 12AX7 is a tremolo oscillator with speed, an intensity control and switch, Ampeg's M-1 module and a footswitch. A 7199 pentode adds gain and its triode works as a split-load phase inverter for a cathode-biased pair of 7591s, with a solid-state bridge rectifier.

• Made in: USA
• Wattage: 18W
• Channels: 1
• Preamp tubes: 1× 12AX7, 1× 7199
• Power tubes: 2× 7591

Tags: american, vintage, tremolo, 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.