Ampeg PBC-228 / PB800 Bass Preamp - Channel One preset

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

A secondary schematic document for the Ampeg PBC-228 bass combo. The PBC-228 used a solid-state circuit with 2×8-inch speakers, offering compact bass amplification for practice and small performances. This document likely covers a revised circuit board or component update issued during the amp's production run through the late 1970s and early 1980s.

• Years produced: 1978–1983
• Made in: USA
• Channels: 1

Tags: american.

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.