Ceriatone Plexi 50 Lead (1972) preset

Verified · 85/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

Ceriatone's Plexi 50 '72 Lead follows the early metal-panel Marshall 50-watt lead circuit: three ECC83s (two input stages, a gain stage with cathode follower, a long-tail phase inverter) and two EL34s on a solid-state rectifier. A large pull-bright cap on the Bright volume and the 4-ohm feedback tap give it a brighter, harder edge. Normal and Bright share bass, middle, treble and presence, no master; effects loop and half-power switch added.

Tags: plexi, el34, crunch, boutique, hand-wired, mid-wattage.

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.