A digital synthesizer sold under the Oberheim name in the Americas and most of Europe. This resulted from the Gibson guitar company, which owned the Oberheim trademarks at the time, licensing the name to the Italian musical instrument maker Viscount in the year 2000. The synth is entirely a Viscount design and has nothing to do with any other Oberheim product.
The OB-12 is a keyboard synth with a four-octave, velocity and aftertouch sensitive keyboard, packaged in a case with a metallic blue panel having white graphics. Standard pitch and mod wheels are provided, as well as a short ribbon controller. As the name implies, it is a 12-voice synth with a voice architecture consisting basically of: two digitally-emulated VCOs with FM capability, a pair of multimode VCFs, two six-segment envelope generators, a ring modulator that accepts the two VCOs as inputs, and two LFOs. Each LFO has a lag processor which can modify the provided waveforms. The synth is multitimbral, capable of playing up to four parts under MIDI control.
An outstanding feature of the OB-12 is its parameter control architecture. Real-time controls are available on the panel for most parameters (not all at once). A feature called the "Motion Recorder" can memorize and play back parameter changes made in real time, and these can be stored with a patch, so that in effect the performer can devise modulations for any parameter, which become part of the patch. A "Morph" capability performs patch changes by gradually changing all parameters from their values in the first patch to their values in the second patch, creating a variety of intermediate timbres; this can be automatic or controlled by the mod wheel. Patch memory consists of 256 patches, which can be dumped or loaded over MIDI.
The OB-12 has been somewhat controversial among performers and Oberheim enthusiasts. The latter in particular denigrate the model as not being true to the Oberheim design philosophy, and the fact that Tom Oberheim was not involved in the design. (There is also some residual animosity towards Gibson stemming from the collapse of Oberheim over the OB-Mx debacle, which reflects on the circumstances of the OB-12.) And Viscount did not help matters by sending the first models out to the field with buggy and incomplete operating systems, which had problems with crashes, random behavior, and some advertised features not working. All of this resulted in slow sales and the end of production (and of Viscount's licensing agreement) in 2005. However, aficionados regard the OB-12 as a good synth in its own right, pointing towards features like the Motion Recorder and the very flexible oscillators. For years, used OB-12s could be had at bargain prices, but there are now very few on the market and prices have gone up.