EICO HF-20 preset

Verified · 91/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The EICO HF-20 is a 20-watt mono valve hi-fi integrated amplifier of the 1950s, sold mainly as a kit. A 12AX7 phono preamp with a multi-position equalisation selector and a second 12AX7 with level, bass, treble and a loudness control feed a 12AU7 amplifier and split-load inverter and a 12AU7 push-pull driver. A pair of 6L6GBs in ultralinear push-pull with global feedback and a 5U4 rectifier make the power; hobbyists still restore and modify them.

• Made in: USA
• Wattage: 20W
• Channels: 1
• Preamp tubes: 2× 12AX7, 2× 12AU7
• Power tubes: 2× 6L6GB

Tags: american, vintage, 6l6, diy, clean.

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.