Bogen CHB-50A preset

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

The Bogen CHB-50A is a 50-watt tube public-address amplifier from the mid-1960s. The two halves of a 6EU7 amplify Mic 1 and Mic 2 (switchable to magnetic phono), each with its own volume, mixed with two aux inputs on an aux volume and a master. A 12AX7 handles bass and treble and a further gain stage, and a 6C4 split-load inverter drives two fixed-bias 6L6GCs with a balance trim, with 70 V line and 4, 8 and 16 ohm taps.

• Made in: USA
• Wattage: 50W
• Channels: 1
• Preamp tubes: 1× 6EU7, 1× 12AX7, 1× 6C4
• Power tubes: 2× 6L6GC

Tags: american, vintage, mid-wattage, clean.

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.