What tubes does the Ampeg Jet J-20 use?

The Ampeg Jet J-20 uses 3× 12AX7 preamp tubes.

When was the Ampeg Jet J-20 produced?

The Ampeg Jet J-20 was produced 2007–2010.

Ampeg Jet J-20 preset

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

The Ampeg Jet J-20 is a 20-watt tube guitar combo from 2007. Bright and normal inputs each get their own triode, summed into one volume and one tone control, followed by a recovery stage and a long-tail phase inverter. A triode tremolo oscillator with speed and intensity modulates the output valves' bias, with a footswitch jack. Two cathode-biased octal output valves run off a 5AR4 tube rectifier with a standby switch.

Years produced: 2007–2010
Wattage: 20W
Channels: 1
Preamp tubes: 3× 12AX7

Tags: american, 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.