Tom Oberheim Son of 4-Voice No Longer Available

4-voice Polyphonic Analog Synthesizer Expansion Module
Item ID: SO4V

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Four Voice Is Back!

Tom Oberheim's SO4V Son of Four Voice heralds the return (in updated fashion) of a legendary analog synthesizer. The original Oberheim Four Voice (and its Two Voice stablemate) were the first commercially available polyphonic synthesizers. You want warm and fat? With 100% discrete analog circuitry, that's what this SEM (Synthesizer Expansion Module) is all about. But the SO4V has significantly more going for it in the way of control than did its dad. You can use SO4V as a 4-voice polyphonic synth, or as four individual synthesizers under MIDI control. It's the wave of the future - and the past: the Oberheim SO4V.

Oberheim SO4V Son of Four Voice Features at a Glance:
  • Four classic SEMs
  • Go ahead, expand...
  • Features its dad never dreamed of
Four classic SEMs

Like the mid-70s original, the Oberheim SO4V is, in reality, four classic Synthesizer Expander Modules sharing the same chassis. The beauty of this arrangement is that you can use it as a 4-voice polyphonic synth - or control it via MIDI as four separate monophonic synths. You can see the possibilities here...

Go ahead, expand...

Two Oberheim SO4Vs can be easily connected together, resulting in eight voices. SEMs - by design - are perfectly suited for stacking. Create the wall of vintage sound that you've heard in your mind's ear, but could never realize - til now.

Features its dad never dreamed of

Tom Oberheim's SO4V design is faithful to the original Four Voice where it counts, and employs modern engineering in the areas where there was room for improvement. As some of the components of the original are - understandably - no longer available, Tom substituted the best replacements he could find. He also replaced original components he "never liked," e.g., the concentric pots. Most importantly, to give modern musicians the control to which they're accustomed, Tom mapped MIDI to the control voltages that drove the original Four Voice. The result is a pure vintage analog synth that gives you control and features that were non-existant in the 1970s. Viewed in that way, the SO4V is very much the realization of a dream. A radically innovative invention, perfected.

Oberheim SO4V Son of Four Voice Features at a Glance:
  • Four classic Synthesizer Expander Modules (SEM)
  • SEMs are 100% discrete analog - no custom chips
  • Voice Control & Programmer retains all features of the original while adding new capabilities
  • Use as a four-voice polyphonic synth or as four individual synthesizers under MIDI control
  • Two MIDI-sync-capable LFOs with multiple waveshapes including sample and hold per voice
  • Two programmable ADSR envelope generators per voice
  • Selectable master tuning (both VCOs or VCO2 only) allows easy detuning for huge unison sounds
  • Polyphonic portamento with linear or exponential response
  • Noise generator connected to filter input #1
  • External audio or A440 tuning reference connected to filter input #2
  • Updated output module with mix and pan control for each voice
  • Two SO4Vs can be easily connected together - result: eight voices!
  • Signature plate--each SO4V comes with Tom Oberheim's signature on the front
If you crave authentic analog synth sounds, the Oberheim SO4V is for you!

Tech Specs

Manufacturer Part Number SO4V

Customer Reviews

See also: Tom Oberheim, Tom Oberheim Synths / Modules