Univox U-250PB - Main preset

Close · 78/100 confidence. Most values readable. Minor gaps filled by inference from similar circuits.

The Univox 250PB is a high-powered bass amplifier from Univox's solid-state lineup, designed for professional bass players requiring substantial low-frequency output in live settings. Its solid-state output section delivers approximately 250 watts with a flat, extended low-end frequency response and a defined mid-range punch. The British-influenced voicing provides upper-harmonic articulation that aids note clarity in dense band mixes, distinguishing the 250PB from more scooped American bass amp designs. At this power level, the 250PB competes with early Ampeg and Sunn bass rigs of the same era.

Tags: british.

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.