FBT S.B.250 / S.B.125 - Main preset

Verified · 90/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The FBT S.B.250 and S.B.125 are solid-state bass amplifiers from this Italian professional audio manufacturer, offering 250 and 125 watts respectively for bass guitar reinforcement. FBT's Italian engineering tradition in professional audio carries over into these purpose-built bass amp designs.

• Years produced: 1970s–1980s
• Made in: Italy
• Channels: 1

Tags: modern, solid-state, bass.

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.