What tubes does the EICO HF-81 - Left use?

The EICO HF-81 - Left uses 2× 12AX7 preamp tubes and 2× EL84 power tubes.

When was the EICO HF-81 - Left produced?

The EICO HF-81 - Left was produced 1958–1966.

EICO HF-81 - Left preset

Verified · 88/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The EICO HF-81 is a stereo integrated tube amplifier kit from the Electronic Instrument Company (EICO) of New York, combining a preamplifier and power amplifier in a single chassis for home stereo use. EICO kits were celebrated for their excellent value and educational assembly experience, making quality hi-fi accessible to American hobbyists. The HF-81 delivers 14 watts per channel of warm EL84 tube tone.

Years produced: 1958–1966
Made in: USA
Wattage: 14W
Channels: 1
Preamp tubes: 2× 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.