Synth’s are made up of several building block components, one of which is the Voltage Controlled Amplifier (VCA) or amp envelope for short. This post explains the amp envelope and demonstrates some common envelope configurations with diagrams and audio examples.
The VCA is always attached to a modulator called an ‘envelope’. The job of the envelope is to control how the volume of the amplifier changes over time. Unlike a compressor which reacts to the incoming signal envelope, the envelope designs the shape using four parameters.
|A||Attack Time||The time is takes to reach full value.|
|D||Decay Time||The time is take from full value to sustain level.|
|S||Sustain Level||The level the note holds while being played.|
|R||Release Time||The times it takes for the note to go from the sustain level to zero once the key is released.|
Common Amp Envelope Configurations
The amp envelope is important because it gives us a way to visualize and manipulate sounds. It’s not something reserved exclusively for synthesizers and electronic music, it is vital for every producer/engineer whether they work with electronic, gangsta rap, ragtime, rock or even bluegrass!