Bogen J50 preset

Verified · 84/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Bogen J50 is a 50-watt tube PA amplifier from the mid-1950s. Two microphone inputs each have a 6SF5 preamp and volume control, and a phono input has its own volume; they mix into a third 6SF5 stage with bass and treble controls. A 6SL7GT amplifies and splits the phase, and a push-pull 6SN7GT driver feeds an interstage transformer driving two 807s with adjustable fixed bias, on 5U4G and 5Y3GT rectifiers, with 70 V and 140 V line taps.

• Made in: USA
• Wattage: 50W
• Channels: 1
• Preamp tubes: 3× 6SF5, 1× 6SL7GT, 1× 6SN7GT
• Power tubes: 2× 807

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.