FBT Bassorgan - Organ preset

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

The FBT Bassorgan is an Italian tube amp with separate Organ and Bass channels, each with two inputs, an ECC83 preamp, bass and treble controls, a volume and a bright switch. A half ECC83 mixes the channels, and an ECC82 gain stage and split-load phase inverter drive a pair of fixed-bias EL503 output tubes on about 365 V. The supply uses silicon diodes. A note on the drawing mentions a special version for a cabinet with two different speakers.

• Made in: Italy
• Channels: 2
• Preamp tubes: 3× ECC83, 1× ECC82
• Power tubes: 2× EL503

Tags: italian, vintage, bass, two-channel.

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.