How Does a Synthesizer Work?

Fundamentals

A synthesizer is a keyboard instrument that shapes the properties of sound waves. Synthesizers use knobs, buttons and sliders to modify the properties of analog or digital signals to produce different variations of a particular circuit or sample. Synthesizers became popular with electronic music in the '70s and '80s and are still widely used today.

Synths 101

A synthesizer usually comes with two wheels for pitch bending and modulation. A pitch bender bends the pitch of a note, while the modulation wheel tends to make the note sound sort of wobbly. Other knobs on the instrument are used to control filters, gain, sweep, wet/dry sound, reverb, and other wave modeling functions. The knob is usually complemented with a wave form picture that represents what aspect of the waveform it is affecting. Some analog synthesizers also come with cable patches that control analog signal flow.

Types

There are many types of synthesizers out there on the market. Brands include Korg, Moog, Dave Smith, Alesis and Roland. Some are strictly analog, meaning that they use analog circuitry to produce noise. Other synthesizers use digital technology to replicate analog circuitry. This is called convolution.