What tubes does the EICO HF-20 - Left use?

The EICO HF-20 - Left uses 1× 12AX7 preamp tubes and 2× EL84 power tubes.

When was the EICO HF-20 - Left produced?

The EICO HF-20 - Left was produced 1956–1965.

EICO HF-20 - Left preset

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

The EICO HF-20 is a 20-watt hi-fi tube amplifier kit from the Electronic Instrument Company (EICO) of New York, designed for home audio reproduction. EICO produced a wide range of electronic kits including hi-fi amplifiers, test equipment, and radio components for the DIY hobbyist market throughout the 1950s and 1960s. The HF-20's EL84 power section delivers warm, musical tone that has attracted audiophile interest.

Years produced: 1956–1965
Made in: USA
Wattage: 20W
Channels: 1
Preamp tubes: 1× 12AX7
Power tubes: 2× EL84

Tags: american, 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.