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Analogue to Digital
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.
Digital Synthesis evolved along with digital recording hardware and software. The first digital synthesizers were revolutionary. The engineering of evermore complex keyboards and stand-alone sound modules became increasingly sophisticated both in the production of high-quality sound and in the techniques of music compositions. The MIDI agreement among the major manufacturers created abundant opportunities for music production and embraced a detailed, deep understanding of music composition and recording.
My first digital 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.
Next I added the digital-analog hybrid, Oberheim Matrix-6 with a velocity sensitive keyboard with 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 digital keyboard with a collection of sampled waveforms that were added together to form patches. The D50 combined samples with analogue-like waveforms and a signal processor to create some unique sounds that became very poular.The D50 had a special ability to create complex, evolving sounds that made it a famous ambient sound generator.
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 prototype 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.EMU became well known for its digital samplers and developed a large library of digital samples for use in synthesizers. I rushed to the music store in 1989 when the sound modules, 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.
I have ongoing attachment to 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.
Equipment manufacturers have created hundreds of keyboard synthesizers and sound modules sporting a range of prices, features, and variations on the basic engineering of sound production equipment. A new buyer faces a proliferation of and potentially bewildering ranges of choices.
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.Electronic Keyboards
Persona Studio Equipment
Persona Digital Studio is located on the Sunshine Coast, Sechelt, British Columbia, Canada.
Persona Music Recordings: Our Music Catalogue includes recorded performances by the P2500 Band, Em4U, and the Persona Classical Consort. Some music online is offered to illustrate music history, advance music education and appreciation. The recordings presented online demonstrate Persona Studio's arranging, recording and mastering techniques. All the recordings are completed in house by Stephen Gislason. The music selections and their history are explained in the book, Sound of Music. Stephen Gislason