OB-X

Introduced in 1979 as Oberheim's bold riposte to the Prophet-5, this synth pioneered a single voice-card design that crammed polyphony into a more portable, programmable package—only about 800 were ever made.

Available in 4-, 6-, or 8-voice configurations, it packs two analog VCOs per voice with classic SEM-derived circuitry using discrete transistors, resistors, and op-amps for that raw, distinctive Oberheim bite, paired with a 12dB/octave lowpass filter, ADSR envelope, and a single LFO. Dual sprung paddle levers handle pitch bend and modulation with intuitive resistance, sitting above a 49- or 61-key synth-action keyboard (velocity-sensitive on some units), polyphonic portamento, sample-and-hold, unison, and chord hold for live expressiveness. A Z-80 microprocessor oversees automatic tuning and 32 onboard patch memories, outputting via a single stereo audio path—no effects, just pure analog tone from its hefty black-panel chassis.

Players still chase its fat, aggressive sound on records from Van Halen to Prince, though some note the original trimpots and components demand careful maintenance today.