Unknown M B I Ii Iii 400 preset

Verified · 80/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The M.B. I/II/III 400 is a high-powered amplifier of uncertain manufacturer, likely a professional or PA-grade design given its 400-watt output rating. The Roman numeral designation suggests a series of related models or channel configurations within a single chassis. Without confirmed manufacturer attribution, full historical context is unavailable.

• Wattage: 400W

Tags: vintage.

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.