What tubes does the Ampeg B-12-XT - Channel One use?

The Ampeg B-12-XT - Channel One uses 2× 12AX7 preamp tubes and 2× 6L6 power tubes.

When was the Ampeg B-12-XT - Channel One produced?

The Ampeg B-12-XT - Channel One was produced 1964–1968.

Ampeg B-12-XT - Channel One preset

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

The Ampeg B-12XT Portaflex was an extended-range variant of the B-12 flip-top series, featuring a larger cabinet and extended bass response. Like its siblings, it used the classic all-tube Ampeg circuit that gave the Portaflex family its legendary warm, round, and authoritative bass tone. The XT designation indicated an extended-bass cabinet tuning, making it popular with players who needed deeper low-end projection in live settings.

Years produced: 1964–1968
Made in: USA
Wattage: 30W
Channels: 1
Preamp tubes: 2× 12AX7
Power tubes: 2× 6L6

Tags: american, vintage, 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.