Ampeg Jet J-12D preset

Verified · 90/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Ampeg Jet J-12-D is a single-channel tube guitar combo built on two 6BK11 compactrons in place of the earlier 6SL7s. Two inputs feed the first gain triode, then a volume and a single tone control; the remaining sections give another gain stage and the phase inverter. The second 6BK11 is the tremolo oscillator and modulator, with speed and an on/off switch. A cathode-biased push-pull pair of 7591As runs off a solid-state bridge rectifier, with feedback from the speaker.

• Made in: USA
• Channels: 1
• Preamp tubes: 2× 6BK11
• Power tubes: 2× 7591

Tags: american, vintage, tremolo.

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.