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Synthesizers, a Brief History

I have played with synthesizers since 1974. I enjoyed making and analyzing  musical sounds, interesting psychoacoustic effects and compared the construction of synthesizers with the construction of the human brain. A synthesizer is built from function-specific modules that are linked together to produce the final results.

When I was first studying electronics, I constructed a synthesizer from modules that each performed one function. The modules had jacks on their front panels so that each could be connected to other modules by using patch cords. To generate musical sounds you connected a piano-like keyboard controller that sent out a different voltage from each key to a voltage controlled oscillator that generated the sound waves at the appropriate pitch. The oscillator was typically connected to a voltage-controlled amplifier that was in turn controlled by a ramp generator, since musical sounds emerge and decay within an amplitude envelope. To finish a convincing musical sound, many modules would be connected in a single path.

Robert Moog created a revolutionary analog synthesizer,  used, for example, by William (Wendy) Carlos's in the popular album Switched-On Bach (1968).  In the 1970s synthesizers become portable keyboard instruments used in live performances.   MIDI (Musical Instrument Digital Interface) made it easy to connect synthesizers with computers and other electronic devices. Software synthesizers appeared in the 1990s.

Analog Synthesis 1974

I started my synthesis career in 1974 with module kits from John Simonton (PAIA). A module kit consisted of a circuit board, transistors resistors and capacitors. There was a circuit schematic and some instructions. You supplied the soldering iron and assembly skills. A basic system required 8 kits, one Voltage Controlled Oscillator, one Envelope Generator, one Voltage Controlled Amplifier, one Low Frequency Oscillator, one Noise Generator, one Low Pass filter and one Band Pass Filter. A power supply was required.

The modules had jacks on their front panels so that each could be connected to other modules by using patch cords. To generate musical sounds you connected a piano-like keyboard controller that sent out a different voltage from each key to a voltage controlled oscillator that generated the sound waves at the appropriate pitch. The oscillator was typically connected to a voltage-controlled amplifier that was in turn controlled by a ramp generator, since musical sounds emerge and decay within an amplitude envelope. To finish a convincing musical sound, many modules would be connected in a single path.

The VCO module produced sine waves, square waves and sawtooth waves. The pitch was determined by a voltage input for a keyboard, for example. The simplest synthesis path was keyboard > VCO > EG >VCA> LPF to BPF > sound amplifier.

Yamaha DX7

My first commercial keyboard was the Yamaha DX7 in 1983.The DX7 was based on Phase  Modulation Synthesis ( Yamaha called it frequency modulation), an innovation in digital technology  that produced remarkably clear instrumental sounds.  The DX-7  became the best selling synth  of  its time and appeared on numerous pop recordings.  The voices included convincing  simulations of the Rhodes electric piano. It used an early implementation of midi and computer based voice editors and librarians became available.  It could only play one voice at a time with  16-note polyphony. It had 32 sound creating algorithms offering different combinations of  6 sound operators.  I recall hours of enjoyment learning to program new sounds.

Oberheim Matrix-6

Next I added the digital-analog hybrid, Oberheim Matrix-6 with a velocity sensitive keyboard and aftertouch. It was limited to 6-note polyphony. A voice was generated by a Digital  oscillator, a VCF, three envelope generators, two ramp generators, portamento and FM controls.  Oberheim sounds were often distinctive and provided  quite a different sound palette than the DX7. The two synths combined nicely.

 Roland D 50

A Roland D50 was the third acquisition, a handsome responsive keyboard with a collection of sample waveforms that were added together to form patches

EMU Proteus

In 1971, Dave Rossum and  friends from Cal Tech built an analog synthesizer they called  E µ . Later with Scott Wedge,  Dave formed a company and the name became E-mu They advertised their products in Popular Electronics and in Electronotes, a newsletter for engineers.  In 1973, E-mu introduced a digitally-scanned polyphonic keyboard, which featured a built-in digital sequencer, the protype of the EMU modules I am using in 2009. In 1979 they were inspired by the high end Fairlight CMI and began designing a sampling keyboard - the E-mulator was first released in 1981.  I rushed to the music store in 1989 when the EMU Proteus first appeared.  This was a truly polyphonic sound module, based on digital samples. The sounds were crisp and clear. Mixes with the Proteus were better that I could achieve with other synths. I have been an EMU Proteus fan ever since.

Korg Trinity

I have ongoing attachment the Korg Trinity and the EMU Proteus 2500, both magnificent electronic devices that contains the equivalent of hundreds of modules and thousands of patch cords. Rather that actually building modules physically and connecting them with real wires, these synthesizers simulate modules and patches by using a digital computer to calculate what the output would sound like if you had a set of modules connected in a certain way. On the Trinity, you choose the "modules" from menus on a touch sensitive screen; then you choose values for many parameters that control the modules and connect modules to form the "patch" or sound that emerges in stereo from the output jacks of the synthesizer. The sound can be a single instrument played expressively, an entire string section or a complex and evolving mixture of sound effects suitable for a Star Wars soundtrack. The synthesizers with virtual modules and dense, variable inner connections provide a modular interconnection concept that can be applied to studying the brain. You combine the knowledge of what each module does with knowledge of how different connections add to, modify and combine the function of individual modules.  

Software Synths

All of the analogue synthesizers worthy of mention have been simulated in software versions.  A number of companies market soft retro synths. For example Arturia offered in 2010 software  package of  7 well-known analog synthesizers: Minimoog V, Moog Modular V, Yamaha CS-80V, ARP 2600 V, Prophet V, Prophet VS and Jupiter-8V. They also offer Analog Factory, a synthesizer  of their own design. These synth simulations are of interest to a range of people and are useful for students who want to learn the basics of analogue synthesis. They can also be used as plugins to software sequencers. The advantages as numerous as disadvantages when used as sequencer plugins. I use software synths to create composition sketches and first drafts but always use hardware sound modules to complete compositions for final recording.

Many of the topics presented online are from Music Notes by Stephen Gislason. Download a free copy of the work in progress. Your comments are welcome.

Persona Digital Studio is located on the Sunshine Coast, Sechelt, British Columbia, Canada. www.personadigitalstudio.com  email  music@personadigitalstudio.com. Our Music catalogue includes recorded performances by the P2500 Band, Em4U, and the Persona Classical Consort. Music downloads are available from iTunes, Napster, AmazonMP3 and from our companion website: Persona Digital Online.  We have enjoyed association with Reverb Nation who provides an online service for musicians to present and market their music.