OB-6 Polyphonic Analog Synthesizer Desktop Module

Born from the genius collaboration between Tom Oberheim and Dave Smith, this desktop module revives the iconic SEM filter's bold, aggressive tone in a compact 6-voice analog powerhouse that's perfect for any rig.

At its heart are two discrete voltage-controlled oscillators per voice, blending continuously variable waveshapes from sawtooth to pulse (with triangle on osc 2), a square wave sub-oscillator, hard sync, and unison mode for thick, unstable detuning. The classic 2-pole state-variable SEM filter delivers low-pass, high-pass, band-pass, and notch modes with resonant bite, modulated deeply via X-Mod from osc 2 or filter envelope to targets like osc 1 frequency, shape, pulse width, cutoff, and filter mode. Dual ADSR envelopes shape filter and amp response with velocity sensitivity, while a versatile LFO offers five waveshapes including random, syncing to internal or MIDI clock, and routing to osc freq, pulse width, filter, or more. Hands-on knob-per-function panel includes a polyphonic 64-step sequencer, multimode arpeggiator, and dual digital effects (24-bit/48kHz reverb, delays including BBD/tape, chorus, flanger, phaser, ring mod, plus analog distortion) with true bypass for pure analog signal path. Polyphonic portamento, aftertouch, and 1000 programs (500 factory, 500 user) round it out in a sturdy 20.75 x 7.8 x 4.4-inch, 13 lb chassis with stereo outs and headphone jack.

Players love its immediate, vintage Oberheim snarl that's more flexible than the originals, with quick programming and standout sequencing that sparks creativity—though some note the digital effects add subtle coloration when engaged.