Ampeg PF-350 Portaflex preset

Close · 72/100 confidence. Most values readable. Minor gaps filled by inference from similar circuits.

The Ampeg PF-350 is a lightweight solid-state bass head in the Portaflex line, about 350 watts into 4 ohms. Its power board pairs a switch-mode supply, with a selectable 115/230-volt input and plus and minus 55-volt rails, with a Class D output stage: a half-bridge of IRFB4227 MOSFETs driven by a gate-driver chip and filtered by an output inductor. Limiter, peak and thermal-mute circuits protect it, with a cooling fan.

Tags: bass, solid-state, modern, high-wattage.

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.