Synthesizers work by manipulating electrical signals which appear as sound when they are used to drive audio amplifiers. These tones are generated by electrical circuits which may work by manipulating a signal through a series of oscillators and filters in an analog circuits in analog synthesizers. They may also perform mathematical manipulation of signals using a microprocessor and digital signal processing in digital synthesizers, or by a combination of both methods.

Synthesized sounds may sound dramatically different than recordings of natural sounds, though sampling synthesizers significantly blur this distinction.

Sound basics

All sounds are comprised of some combination of pure sine waves. Generally, a single sound will include a fundamental frequency, and any number of overtones. The frequencies of these overtones are either integer multiples of the fundamental frequency, or integer fractions thereof subharmonics.

When natural tonal instruments sounds are analyzed in the frequency domain, the spectra of their sounds will exhibit amplitude spikes at each of the fundamental tone harmonics. Some harmonics may have higher amplitudes than others. The specific set of harmonic versus amplitude pairs is known as a sound's harmonic content.

Well known Brands of Programmable synthesizers

A vast range of programmable synthesizers are available in the market. All the famous brands have come out with their latest synthesizers. In this article we will be discussing three of the most famous and widely used programmable synthesizers.

S08 Programmable Synthesizer from Yamaha - The S08 features an 88-key balanced hammer design with Initial Touch, plus full 64-note polyphony. With its sleek, lightweight portable design, palette of high quality sounds and advanced storage features, the S08 makes an ideal primary or additional instrument for the songwriter, arranger, live performance musician, studio musician, and amateur alike.

Users can create their own sounds and store them in any of 128 user-voice memory locations. Onboard effects include chorus, reverb and variations. Panel switches, a large LCD display and controllers that include pitch bend, a mod wheel and a numeric keypad, provide full control and quick access to all functions.

Roland XP-30 - The XP30 uses sound sets from the popular JV-1080 and JV-2080 modules, plus tons of sound patches from the Session, Orchestral, and Techno Collection expansion boards. Having two slots for SRJV 80 expansion boards, the XP-30 has 61 velocity sensitive keys with after touch.

It also has built-in reverb, chorus, and set of forty effects, four onboard sliders for real time control and editing and patch finder and phrase preview functions.

Korg RADIAS - The Korg RADIAS keyboard is a 49-key, 24-voice polyphonic programmable modeling synthesizer and 16-band vocoder instrument, based on the proprietary MMT modeling technology sound engine. The synthesizer offers a variety of synthesis algorithms together with multiple effects, advanced comb filter and wave shaping features, modulation sequencing, and formant-motion vocoding.

The RADIAS offers an innovative, custom-configurable design with a control module that can be used independently or teamed with the unique dedicated keyboard, creating an integrated performance instrument offering classic, current and futuristic sounds accessible from a familiar, old-school, knobs-and-buttons programming interface.