Davoli 1000-Series EL500/EL504 Power Unit preset

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

This sheet covers three versions (a, b and c) of the Davoli (Krundaal) 1000-series valve power unit, with no preamp or tone controls. An ECC82 serves as input stage and phase splitter with feedback from the output transformer, an ELL80 dual pentode drives the output, and a pair of EL504s (versions a and b) or EL500s (version c) run in push-pull with adjustable fixed bias into 100-, 60- or 40-rated output transformers.

• Made in: Italy
• Channels: 1
• Preamp tubes: 1× ECC82, 1× ELL80
• Power tubes: 2× EL504

Tags: italian, vintage, power-amp.

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.