FBT 500 R2 - Channel 1 preset

Verified · 90/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The FBT 500 R2 is an Italian two-channel tube amp from about 1972 with reverb and tremolo. Each channel has high and low inputs, an ECC83 with treble, bass and volume and a bright switch. An ECC82 gain stage and split-load phase inverter drives a pair of fixed-bias EL503 output tubes into an 8-ohm speaker. An ECC83 tremolo has frequency, intensity and a footswitch, and the Hammond spring reverb is driven by an ECL82 and recovered by half an ECC83, with its own level and a switch.

• Made in: Italy
• Wattage: 50W
• Channels: 2
• Preamp tubes: 4× ECC83, 1× ECC82, 1× ECL82
• Power tubes: 2× EL503

Tags: italian, vintage, reverb, tremolo, 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.