Bogen CHB-20A - Mic preset

Verified · 88/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Bogen CHB-20A is a 20-watt tube PA amplifier from this American commercial audio company, built for institutional public address applications with multiple microphone inputs. Bogen PA amplifiers of this era were common fixtures in schools, auditoriums, and public spaces, valued for their reliable performance and honest audio reproduction. These units have found second lives in the guitar and recording communities as characterful vintage tube amplifiers.

Tags: american, 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.