What tubes does the Ampeg SB-12 - Bass use?

The Ampeg SB-12 - Bass uses 3× 12AX7 preamp tubes and 2× 6L6 power tubes.

When was the Ampeg SB-12 - Bass produced?

The Ampeg SB-12 - Bass was produced 1962–1968.

Ampeg SB-12 - Bass preset

Verified · 82/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The SB-12 is a compact flip-top bass combo with a 12-inch speaker, providing the essential PortaFlex bass character in a lighter package. The Bass channel is specifically optimized for bass guitar, with EQ voiced to enhance fundamental low-end response. A practical alternative to the heavier B-15N for smaller venues and studios.

Years produced: 1962–1968
Made in: USA
Wattage: 25W
Channels: 2
Preamp tubes: 3× 12AX7
Power tubes: 2× 6L6

Tags: bass, 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.