FBT Bassorgan 500 BR (2-input) preset

Verified · 86/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

This version of FBT's Bassorgan 500 BR is a single-channel amplifier with two inputs, distinct from the two-channel Bass/Organ model. Two ECC83 gain stages and an ECC82 split-load phase inverter drive a pair of EL503 output pentodes, a straightforward tube circuit for bass or keyboard.

• Made in: Italy
• Channels: 1
• Preamp tubes: 2× ECC83, 1× ECC82
• Power tubes: 2× EL503

Tags: italian, vintage, bass, clean.

Schematic-derived preset files for the Neural DSP Quad Cortex and 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.