What tubes does the Ampeg SJ-12T - Guitar use?

The Ampeg SJ-12T - Guitar uses 3× 12AX7 preamp tubes and 2× 7591A power tubes.

When was the Ampeg SJ-12T - Guitar produced?

The Ampeg SJ-12T - Guitar was produced 1963–1967.

Ampeg SJ-12T - Guitar preset

Close · 78/100 confidence. Most values readable. Minor gaps filled by inference from similar circuits.

The SJ-12T is a guitar-specific amplifier from Ampeg's SJ series with 7591A output tubes. The Guitar channel is voiced for electric guitar with an EQ curve emphasizing clarity and note articulation. The SJ designation indicates a studio/jazz-oriented voicing with clean, detailed tone reproduction.

Years produced: 1963–1967
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.