CHAPTER IV: VOICE PROGRAMMING

1.The Basics of FM Synthesis

Before you begin actually programming or editing your own voices, a basic understanding of how digital FM synthesis works will be necessary. In the following explanation, we will learn how the DX27’s FM voice generator produces complex voices. This information will help you to understand the process and make it easier for you to create and edit your own voices.

OPERATORS

The Yamaha DX series FM digital synthesizers use pure sine waves that interact to create the full harmonic spectrum for any voice. Each digital sine wave oscillator is combined with its own envelope generator to form an “operator.”

Note that the operator’s oscillator has two inputs: one for the oscillator pitch data, and one for modulation data.

CARRIERS AND MODULATORS

The DX27 voice generator has 4 operators. When the output of one operator is fed to the modulation input of a second operator, i.e. the first operator modulates the second, a whole spectrum of harmonics is created that can form an incredibly diverse range of complex waveforms (including the more conventional triangle, sawtooth, and square waveforms). All this from just two operators!

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