What tubes does the Ampeg B-15S Rev D - Channel Two use?

The Ampeg B-15S Rev D - Channel Two uses 3× 12AX7 preamp tubes and 2× 6L6 power tubes.

When was the Ampeg B-15S Rev D - Channel Two produced?

The Ampeg B-15S Rev D - Channel Two was produced 1967–1972.

Ampeg B-15S Rev D - Channel Two preset

Verified · 85/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The B-15S Rev D is a late-revision PortaFlex bass combo documenting factory updates made to improve reliability and tone in the final years of B-15S production. Channel One retains the classic warm PortaFlex bass character. Rev D refinements include improved power supply filtering and updated component values.

Years produced: 1967–1972
Made in: USA
Wattage: 30W
Channels: 2
Preamp tubes: 3× 12AX7
Power tubes: 2× 6L6

Tags: bass, american, vintage, low-wattage, clean, studio.

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.