The Operator FM Synth
The available controls in Operator are based on the signal path of a hardware synthesizer, such as the Synclavier or the Yamaha DX-7. When a note is triggered, a digital waveform is played back to create the basic note. Operator has over two dozen to choose from, or you can draw your own into the main display window using the pen tool. The amplitude waveform, controlling the progressive volume of the sound, is drawn with a standard ADSR line diagram, representing the attack, decay, sustain and release of the sound.
The left side of the main display houses four separate frequency modulation controls. These are the primary controls for reproducing the classic FM sound. Each control controls the relation of the oscillator frequency to the note pitch. Allowing the user to create a variety of harmonics and overtones to add complexity and texture to each note. This method of sound generation is identical to the one used in hardware FM synthesizers
As the Operator mimics a digital device, rather than an analog one, your computer is able to perform the exact same mathematical process that occurs inside a hardware unit. This produces a very authentic approximation of the original machines, and using the same types of controls and parameters will make the device easier to use for those already familiar with existing synthesizers. Synths such as this one are a common inclusion in most audio software packages.
The Ableton Live Operator presets are designed to show off all the features of the synth. In particular, its ability to emulate the classic synthesizers on which it is based. There are emulations of classic signature sounds, and a number of "retro" patches.
They're also intended to familarize you with the effects of altering the controls. Having a variety of pre-made sounds will allow you to instantly observe the impact that altering a particular control will have. To allow further experimentation, Ableton includes a "Hot Swap" button on the title bar of Operator. Enabling Hotswap mode allows you to instantly switch between presets while the sequencer is playing, making it useful for browsing a variety of different sounds and hearing them in context of a song.