This is part four of a qualitative analysis of the DX7 Envelope Generator. The series begins here . Part three is here Rising segments.

Part two is here Extracting the envelope. We concluded part two finding out that the DX7 envelope generator’s curves were:

Part one is here A closer look at an operator envelope. Let’s begin our understanding of the envelope generators by trying to answer the easier question: what kind of shape the envelope segments have.

Silence, sine waves and trigonometry. The Yamaha DX7, an FM synthesizer released in 1983, should need little or no introduction.