This tiny article on the EMS polysynthi was published in the International Musician magazine (USA) february 1980, as an announcement for the Frankfurter Messe, where the synths would be demonstrated by EMS (please note that EMS was located at the Putney bridge road by then 🙂 Please note that all (c) are with International Musician magazine and the author. We’ve added some images and an EMS Polysynthi demo video for your convenience.

The emergence of synthesizers as a stage instrument brought about a new age in modern music. Not only were a myriad of instrument sounds at the h9nds of a single player, if the synthesiser is polyphonic, all these sounds could be played at once by one musIcIan. But how does this player effectively co-ordinate all those parts as if they were an orchestra? This dilemma was overcome by the inventors of the EMS Polysynthi. The Polysynthi is not an ordinary synth, not even an ordinary polyphonic synth. The Polysynthi was designed from scratch to-be the most rapidly and easily played polyphonic synth built. A completely stable, easily tuned o.sciHator bank covering nine octaves is the primary sound source. A four-octave standard keyboard with three simultaneous outputs – polyphonic, position dependent CV and pressure dependent CVactivates the oscillator bank. There are two voltage controlled LFO’s with variable waveforms and the two ADSR’s with LED indicators are triggerable from either VC LFO or from the key board. ADSR 1 may be triggered from the envelope follower. An analogue delay line can provide echo, chorus, flanging and reilerb effects. The Polysynthi features LED indicators and colour coded source, control and treatment panels for rapid operation. The LED’s indicate control voltage switching and the colour coded, logically layed out panel shows a wide range of easily patched, repeatable effects. An optional add-on poly-phonic sequencer, using advanced microprocessor circuits, can edit and commit to memory ten minutes· of polyphonic music.

As well as producing 49 simultaneous outputs through three alternative waveforms, the VCO bank has a range switch to move octaves produced from 1′ to 32′. The VCO’s can be tuned to other instruments and their circuitry is drift free. Pitchbend is controlled by a centre sprung red coded knob or footpedal. Keyboard Memory determines . infinite sustain or no sustain. The ADSR release is set to short automatically when keyboard memory is off. White noise or an external input -can be mixed with the oscillator bank before being sent through the filter. Balanced or unbalanced, line or microphone, high or low impedance inputs are accepted through the rear panel. If no external input’ is used, the Polysynthi can produce various effects with a VCO bank feedback signal. The low-pass, switchable VCF is of the two or four pole voltage controlled type. ADSR and LFO voltage can be used to control it and ADSR I can sweep the filter frequency by any amount set on the “Direct Control” knob. Frequency can also be controlled by a footpedal. The VCA can be controlled in the same way·, and a pedal can be used to control its amp I itude.

The Polysynthi’s Analogue Delay Line uses an output voltage from the VCA, and, remixed with the original signal, gives a +4dB low impedance signal. Delay time of the various echo, reverb and chorus effects can be controlled by either ADSR, LFO or keyboard voltage. A switch selects long or short delay time ranges and another, chorus or Echo mode. The 49-note C-C keyboard, as well as providing polyphonic information to the VCO’s, produces two control voltages. One corresponds to the highest note. played and the other is pressure pfoportional. Jack sockets for output; input i3nd three pedals are fitted to the Polysynthi back panel and can be switched for Iine or microphone. Provision is made for the fitting of the optional Sequencer.

Music synthesis is a new art, unfortunately many musicians hqven’t really begun. to appreciate its possibilities. We’re proud to offer the EMS Polysynthi because EMS synthesizers are, leading the synthesizer world the WiiY they have for the last seven years. Mariy. of today’s tpp selling synth items were first commercially developed by EMS including the Vocoder and peg patch synthesizers. Now the Polysynthi reaches out to the “state of the art” boundaries on synthesis.