Ampeg B-3158 (power amp) - Main preset

Close · 73/100 confidence. Most values readable. Minor gaps filled by inference from similar circuits.

The B-3158 power amp schematic documents the output section of a mid-power Ampeg solid-state bass combo. The Main power stage delivers clean, reliable bass amplification. Part of Ampeg's late-1980s solid-state bass combo lineup aimed at the working bassist market.

• Years produced: 1988–1993
• Made in: USA
• Wattage: 150W
• Channels: 1

Tags: bass, american, modern, mid-wattage, solid-state.

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.