Analog synthesizers consist predominantly of basic modules that will be explained here. The principle is on most cases the following: Certain parameters, which are affecting the sound are influenced by control voltages (CV). These modules can occur more than once in one synthesizer. In the first devices in the 1970s, so called modular systems - often covering whole studio walls - could be assembled in every way the musicians wanted by connections with patch cables. In later models like the Minimoog the modules were hardwired. A typical constellation consists of several voltage controlled oscillators (VCO) that create the sound, after mixing them together the sound is filtered by a voltage controlled filter (VCF) and then the amplitudes are shaped by a voltage controlled amplifier (VCA). It is the purpose of this site to describe these and other feartures.

Synth Modules
VCO - Voltage Controlled Oscillator
VCF - Voltage Controlled Filter

VCA - Voltage Controlled Amplifier
ADSR - Attack, Decay, Sustain, Release Envelopes
LFO - Low Frequency Oscillator
Noise Generators

Synthesis Methods

In the so called subtractive synthesis oscillators create a certain frequency spectrum and in the next steps of the synthesis some frequencies are cut out of the spectrum by filters. This is in contrast to the additive synthesis, where the sound is created by addition of sine waves. In frequency modulation  (FM) synthesis the idea is to modulate the frequencies of the oscillators by other oscillators to create particular sounds.

Subtractive Synthesis
Additive Synthesis