What tubes does the Davoli UP4 EL504 use?

The Davoli UP4 EL504 uses 4× EL504 power tubes.

When was the Davoli UP4 EL504 produced?

The Davoli UP4 EL504 was produced 1966–1974.

Davoli UP4 EL504 preset

Close · 70/100 confidence. Most values readable. Minor gaps filled by inference from similar circuits.

The Davoli UP4 EL504 is a four-tube power unit module from Davoli's UP series, using Italian EL504 beam tetrodes as the output device. This modular power section was a key component in Davoli's high-power stack configurations, compatible with the full range of Davoli preamplifiers.

Years produced: 1966–1974
Made in: Italy
Channels: 1
Power tubes: 4× EL504

Tags: vintage.

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.