An analog synthesizer is an instrument that uses analog circuits and analog computer techniques to create sound electronically. A very specific form of this synthesizer was the analog vocoder, which is based on equipment developed for speech synthesis. This hugely popular musical instrument can be used both as a sound generating and a sound processing system.

A brief history of Analog Synthesizers

Trautonium is the earliest synthesizer, which used a variety of valve and electro mechanical technologies. It was invented in 1928. Early versions of this instrument used technology, which was derived from electronic analog computers and laboratory test equipment. These were mostly replaced by digital synthesizers and samplers over the early mid 1980s. In 1978, the first microprocessor controlled system was created and introduced.

Different modules of Analog Synthesizers

They were found in various modules when they were first introduced. Because many of these modules took input sound signals and processed them, an analog synthesizer could generate and process sound simultaneously. Below are some of the modules, which were commonly found in an analog synthesizer.

VCO

Voltage Controlled Oscillator is the most commonly used source module. It generates a steady signal at a preset pitch. The signal is usually available in a variety of waveforms that are selected by the patch connection.

VCA

Voltage Controlled Amplifier changes the amplitude of a signal and they usually have a very wide frequency response.

VCF

Voltage Controlled Filters. Most of the sound flexibility of an analog synthesizer comes from the filters.

Envelope Generators

An envelope generator produces and controls voltage that rises and falls according to a voltage command. Envelope Generators also control voltage of some parameters, delay start and end the release pulse.

LFO

Low Frequency Oscillator has an output of low frequency waveform and the output is usually in a sine or triangle wave. It is also used as a control voltage for some other modules. For example it can be used to modulate the frequency of a VCO.

Ring Modulators

When two signals are merged on a ring modulator, it gives a distorted frequency.

Sequencers

Sequencers allow you to preprogram a tune with a set of knobs.

Reverb Units

Sound Mixers

All analog synthesizers have some simple sound mixers to allow the combination of signals.

Many people and companies manufacture this popular instrument. But the most famous and most widely used of them are

A Moog Synthesizer

An Emu Modular

A Synton

A homemade machine

Conclusion

Analog synthesizers have developed themselves in time to make a permanent place in the world of synthesizers. Even though digital synthesizers are the ones, which are most widely used; the professionals and sound technologists prefer analog synthesizers still now.

After the introduction of digital synthesizers the musicians who did not want to spend big money for these systems, started using the analog ones. This gradually led to an increase in demand of the analog brands in the mid 1990's. They became increasingly popular due to their unique modules, which consisted of a number of independent electronic modules connected by patch cables.