OB-6 Polyphonic Analog Keyboard Synthesizer

Born from the dream team-up of Tom Oberheim and Dave Smith, this synth revives the raw, aggressive SEM tone that defined '70s polyphonics, but packs it into a modern 6-voice hybrid powerhouse ready for today's studios.

At its heart, two discrete analog VCOs per voice deliver continuously variable waveshapes—from sawtooths to pulses, with triangle on osc 2, plus a square sub-octave on osc 1 and hard sync for thick, unstable detuning. The classic 2-pole state-variable filter nails Oberheim's low-pass, high-pass, band-pass, and notch modes with resonant bite, driven by dedicated ADSR envelopes for filter and amp, both velocity-sensitive. X-Mod lets osc 2 or the filter envelope twist osc 1 freq, shape, pulse width, or filter params for wild timbres, while a versatile LFO with five shapes (including random) hits osc freqs, pulse widths, cutoff, and more. Hands-on knob-per-function panel includes pitch/mod wheels, a 49-key semi-weighted keyboard with velocity and aftertouch, poly step sequencer up to 64 steps, arpeggiator, and 1000 programs. Dual 24-bit/48kHz digital FX—reverb, delays (BBD/tape), chorus, flanger, phaser, ring mod, plus analog distortion—layer in via true bypass to keep the signal pure analog. It's compact at 32 x 12.7 x 4.6 inches and 20 lbs, with dual mono outs and headphone jack.

Players love its immediate, knob-tweaky workflow and that unmistakable Oberheim aggression—fat leads, lush pads, punchy basses—that outshines vintage units in flexibility, though some note the 6-voice limit feels tight next to beefier modern polys.