Ampeg B3158 preset

Verified · 86/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Ampeg B-3158 is a mid-1990s solid-state bass amp with a built-in bi-amp power section. After the preamp, an effects loop and a balanced XLR direct out with pre/post and -20 dB pad switches, the signal splits into separate low- and high-frequency power amps, each an op-amp driver into Darlington TIP142/TIP147 output transistors with its own optocoupler limiter, feeding 4-ohm low and 8-ohm high speaker jacks.

• Made in: USA
• Channels: 1

Tags: american, bass, 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.