Analog synthesizer

First generation modular synthesizers

Early analog synthesizers used technology derived from electronic analog computers and laboratory test equipment. They were generally "modular" synthesizers, consisting of a number of independent electronic modules connected by patch cables.

Synthesizer modules found in early analog synthesizers included:

• voltage controlled oscillators[?]
• voltage controlled filters[?]
• voltage controlled amplifiers[?]
• envelope generators[?]
• low frequency oscillators[?]
• ring modulators[?]
• reverb units[?]
• sequencers
• sound mixers[?]

Because many of these modules took input sound signals and processed them, an analog synthesizer could be used both as a sound-generating and sound-processing system.

Famous modular synthesizer manufacturers included Moog, Arp Intruments[?], and Electronic Music Studios[?].

Moog established de-facto standards for analog synthesizer control interfacing, using a logarithmic 1-volt-per-octave pitch control and a separate pulse triggering signal. These control signals were routed using the same types of connectors and cables that were used for routing the synthesized sound signals.

A very specialized form of analog synthesizer was the analog vocoder, based on equipment developed for speech synthesis. Vocoders could be used to make a sound that resembled a musical instrument talking or singing.

First generation all-in one synthesizers

Later analog synthesizers used the same building blocks, but integrated them in a single unit, eliminating the patch cords in favour of an integrated signal routing system. The most popular of these was the Minimoog.

Famous makers of all-in-one analog synthesizers included Moog, Arp, Korg[?] and Yamaha. Because of the complexity of generating even a single note using analog synthesis, most synthesizers remained monophonic.

Second generation all-in one synthesizers

A second generation of analog synthesizers emerged later, with limited polyphony, typically supporting four voices. Oberheim[?] was a notable manufacturer of analog polyphonic synthesizers.

The Polymoog[?] was an attempt to create a truly polyphonic analog synthesizer, with sound generation circuitry for every key on the keyboard. However, its architecture resembled an electronic organ[?] more than a traditional analog synthesizer, and the Polymoog was not widely imitated.

Third generation all-in one synthesizers

In the 1980s, the first microprocessor-controlled analog synthesizers were created by Sequential Circuits[?]. These used microprocessors for sytstem control and control voltage generation, including envelope generation, but the main sound generating path remained analog. The MIDI interface standard was developed for these systems. This generation of synthesizers often featured six or eight voice polyphony.

With the falling cost of microprocessors, this architecture became the standard architecture for high-end analog synthesizers.

The fall and rebirth of analog synthesis

Analog syntheisizers were mostly replaced by digital synthesizers and samplers over the late 1980s and early 1990s. In the late 1990s, a fashion emerged for "retro" analog synthesizers, with their proponents claiming that the "analog sound" of old analog synthesizers was better than the sound of current digital synthesizers. This led to the construction of a new generation of analog synthesizers, including modular synthesizers.

External links

• ARP synthesizer patents (http://www.till.com/articles/arp/patents)