3.12 Example instruments
3.12.1 Moog modular (1965)
The Moog modular synthesizers comprise a number of modules which are placed in a frame which provides their power. Connections between modules are made using ¼-inch front panel jack connectors. Models were available where the number and choice of modules were pre-determined, or the user could make their own selection. The system shown here (Figure 3.12.1) provides enough facilities for a powerful monophonic instrument, although producing polyphonic sounds does require a large number of modules, and can be very awkward to control.
FIGURE 3.12.1 Moog modular.
Note the logical arrangement of the panels: the controls are at the top and the sockets at the bottom. Although with two rows of modules, the patch-cords do tend to obscure the lower set of mostly VCO controls.
3.12.2 Minimoog (1969)
The Minimoog was intended to provide a portable monophonic performance instrument (the Sonic Six repackaged similar electronics in a different case for educational purposes). It provides a hard-wired arrangement of synthesizer modules: VCOs, VCF, VCA, with two ADS EGs. This topology has since become the de facto 'basic' synthesizer 'voice' circuit, and can be found in many monophonic and polyphonic synthesizers, as well as custom 'synth-on-a-chip' ICs (Figure 3.12.2).
FIGURE 3.12.2 Minimoog.
3.12.3 Yamaha CS-80 (1978)
The Yamaha CS-80 was an early polyphonic synthesizer made up from eight sets of cards, each comprising a dual VCO/VCF/VCA/ADSR type of synthesizer 'voice' circuit. Comprehensive performance controls made this a versatile and expressive instrument, if it was little bulky and heavy. Preset sounds were provided and these could be layered in pairs. Four user memories were provided, these used miniature sliders and switches which echoed the arrangement of the front panel controls, which provided another two user memories. The presets could be altered only by changing the resistor values on a circuit board inside the instrument (Figure 3.12.3).
FIGURE 3.12.3 CS-80.
3.12.4 Sequential Prophet 5 (1979)
The Prophet 5 was essentially five 'Minimoog'-like synthesizer voice cards connected to a polyphonic keyboard controller. The major innovation was the provision of digital storage for sounds, although the ability to use one VCO to modulate the other, called 'poly-mod' by sequential, allowed the production of unusual FM sounds (Figure 3.12.4).
FIGURE 3.12.4 Prophet 5.
3.12.5 Roland SH-101 (1982)
The SH-101 was intended for live performance and contained a simplified basic synthesizer 'voice' circuit. The instrument casing was designed so that it could be adapted for on-stage use by slinging it over the shoulder of the performer – a special hand grip add-on provided pitch-bend and modulation controls (Figure 3.12.5).
FIGURE 3.12.5 SH-101.
3.12.6 Oberheim Matrix-12 (1985)
The Matrix-12 (and the smaller Matrix-6) was a modular synthesizer in a case which was more typical of a performance synthesizer. The front panel extends the use of displays, which was pioneered in earlier OB-X models – this time using green cold-cathode displays, to provide reassignable front panel controls. The wide range of processing modules made this a versatile and powerful instrument. Only 1 voice from the 12 available is shown in Figure 3.12.6.
FIGURE 3.12.6 Matrix-12.
Printed with permission from Focal Press, a division of Elsevier. Copyright 2009. "Sound Synthesis and Sampling" by Martin Russ. For more information about this title and other similar books, please visit www.elsevierdirect.com.
For more articles like this and others related to audio design, visit Audio Designline and/or subscribe to the monthly Audio newsletter (free registration).