Synthacon

Back in 1975, this wedge-shaped powerhouse emerged from Salt Lake City as a hand-built rival to the Minimoog, packing three voltage-controlled oscillators into a portable frame that delivered fat, stable tones without the fuss of a full modular setup.

Its heart is a trio of analog VCOs offering sawtooth, triangle, square, pulse, sine waves, plus white and pink noise, spanning from subsonic lows under 0.1 Hz to ultrasonic highs over 20 kHz. The star is Nyle Steiner's 12dB/octave 2-pole multimode filter—resonant low-pass, high-pass, or band-pass—that self-oscillates without the volume drop you get on a Moog, thanks to positive feedback and reverse polarity. Two ADSR envelopes shape the VCA, filter, and oscillators, while sample-and-hold, portamento, pitch bend, and switch-based routing add modulation magic via 26 knobs, 3 trimmers, and 43 switches across ten sections on its 49-key keyboard panel. CV/Gate outs let it drive external gear, all in a durable, silver-faced design with wood sides.

Only a few hundred were handmade before production ended in 1979, making it a rare gem sought by players like Frank Zappa and John Paul Jones for its boutique sound—brassy leads, windy textures, and snarling basses that still inspire modern recreations.