OB-8 is the last representative of the classic OB series – it’s an improved version of the OB-Xa synthesizer.

OB-8, as well as the whole series of vintage OBs, is built on using voice cards, but unlike its predecessors it was produced with a fixed number of voices, there are eight of them in the synthesizer.

There are two VCOs, VCF, VCA and two envelope generators per voice card.

Each voice is composed of a signal from two voltage controlled oscillators (VCO) which produce a saw, a triangle and a meander with different duty cycles. VCOs are based on specialized Curtis CEM3340 microchips widely used in synthesizers of the beginning and the middle of the 80s.

The voltage-controlled filter (VCF), as well as in OB-SX and OB-Xa, is not discrete, but is built on CEM3320. VCF is a resonant low-pass filter with a slope of 12 or 24 dB per octave. There’s a dedicated envelope generator provided to the filter featuring the adjustment of attack time, decay, sustain and release.

The voltage-controlled amplifier (VCA), depending on the revision, is built either on discrete elements or on the CEM3360 chip. The VCA also has an ADSR envelope generator built on the Curtis CEM3310 chip.

OB-8 operating system allows you to save up to 120 presets, 12 types of keyboard split and layering. The arpeggiator was included in the synthesizer with the possibility of external control (not MIDI). In the later revisions of the synthesizer the MIDI interface was supported.

The synthesizer can be heard in the tracks of Styx, Depeche Mode, Tangerine Dream, KLF, Simple Minds, Ministry, Nine Inch Nails, Pet Shop Boys, Art of Noise, Queen, Van Halen, Prince.