Gibson BR-1 - Microphone preset

Verified · 80/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The BR-1 is an early post-war Gibson amplifier made for lap steel. One input runs through a pentode stage to its own volume control, while two more inputs share a second volume; both feed a twin-triode stage, then a tone control and a twin-triode phase inverter driving a push-pull pair of output valves with feedback from the output transformer. A full-wave valve rectifier and field-coil speaker complete it. Valve types are not printed on the drawing.

Tags: american, vintage, 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.