What tubes does the Ampeg J-12D Jet - Normal use?

The Ampeg J-12D Jet - Normal uses 3× 12AX7 preamp tubes and 2× 7591A power tubes.

When was the Ampeg J-12D Jet - Normal produced?

The Ampeg J-12D Jet - Normal was produced 1962–1966.

Ampeg J-12D Jet - Normal preset

Verified · 88/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The J-12D Jet is a mid-1960s guitar combo using the distinctive 7591A output tubes favored by Ampeg during this period. The Normal channel provides a clean, midrange-forward tone with natural 7591A compression. The Jet series combos were among Ampeg's most popular guitar amplifiers before the bass market dominated the company's focus.

Years produced: 1962–1966
Made in: USA
Wattage: 18W
Channels: 2
Preamp tubes: 3× 12AX7
Power tubes: 2× 7591A

Tags: guitar, american, vintage, low-wattage, clean.

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.