Eico 3420 (1968)

The Eico 3420 is a monophonic, tube-driven analog synthesizer sold as a kit for $59.95. Past that, the documented record is thin. It is classified as an "educational" instrument - MatrixSynth calls it "an educational music synthesizer" - and SynthArk likewise describes it as a completely analog, monophonic unit. Collectors often call it a "toy" synth, a label that reflects its educational bent and kit origins more than any formal pejorative.

What's known about the 3420 is mostly circumstantial. Eico was a well-established name in kit electronics. The company built its reputation on test equipment and hi-fi components that hobbyists assembled at home, so a $59.95 synthesizer kit fits the house pattern. But no detailed signal-flow documentation, oscillator/filter architecture, or technical specifications have surfaced in the research. There's no keyboard size, no frequency response, no dimensions on record.

The production date is in conflict. SynthArk and MatrixSynth both give 1968, while a MatrixSynth listing for a specific unit says it "dates from 1971." Whether that later date reflects a particular unit's manufacture or a production run extension is unclear, so the header stays at 1968 with the caveat noted here. HiFI-Stereo (September 1971, p.20) covered new products in the period, but the 3420 doesn't appear in the surviving chunk of that issue. A kit synth likely aimed at beginners and schools wasn't necessarily headed for the pages of the hi-fi press.

Known specs, such as they are: