image from a Microcon brochure courtesy of Kevin Lightner
"The Steiner [not Steiner-Parker though the model pictured does say Steiner-Parker] Microcon is a complete synthesizer (less keybaord) in a single module. It has its own power supply, VCO, LFO, VCF and envelope generator, thereby combining all of the most needed parts of a synthesizer in one unit.
"It can be used with synthesizer accessories such as sequencers, electronic valve instruments, guitar slave-drivers, pitch followers, or with a keyboard. Multiple units can be combined with a guitar controller to form full polyphonic synthesizers at a fraction of the cost normally expected. Combined with a regular synthesizer, it ads an extra 'voice' to your present system.
"Oscillator stability and tracking are the best that state of the art will allow. Numerous inputs and outputs are available on the front and top of the unit. Other signals available inside can be brought out for special applications, and connected to other equipment in a variety of useful ways."
The Minicon truly packs alot of synthesizer into a small space (which looks to be about 4-inches by 6-inches. There are 8 knobs and 6 switches. The VCO has knobs for course and fine tuning and switches allowing selection of "three waveforms". The LFO has knobs for rate and level and a switch for beat and is available for vibrato. The VCF has knobs for frequency and gain, as well as a switch for resonance. The Envelop Generator has knobs for attack and decay, as well as a switches to enable damp (a quick release decay) and sustain. The VCA is described as a "trigger controlled audio gate". Connections include positive and negative trigger out, VC filter in, calibrated and uncalibrated voltage control ins, a signal out (which "can be paralleled"), and a trigger in. According to the product literature the "beat function causes the VCO to sound like to sound like two oscillators beating together."
The Minicon was rumored to be used as the synthesizer innards of the Hagstrm Patch 2000 guitar synthesizer.
[from a Microcon brochure courtesy of Kevin Lightner]