Oscillators & Operator Display
Most standard synthesizers can be broken down into a few core sections, each performing their own role in the sound sculpting process.
Although Operator is a complex synth, the building blocks are no different.
Here’s Operator broken down into sections:
1. Oscillator Section
Oscillators are the original sound source of a synthesizer. They create the audio signal that is then fed through the rest of the synthesizer’s signal path.
Oscillators can generate different waveforms that each have their own unique harmonics and, therefore, unique timbre. The most common oscillator waveforms are Sine Wave, Saw Wave, Triangle Wave, and Square Wave.
Open your Module 4 Live Pack and check out the Operator device in the track titled Operator. Make sure the track is armed and that your Computer MIDI Keyboard button is turned on if you aren’t using a MIDI controller. As a reminder, that’s this guy:
Play a few notes. What you’ll hear right off the bat is a Sine Wave.
Its waveform looks like this:
It is smooth and doesn’t have any harmonic overtones. Sine waves are the simplest kind of wave shape and, theoretically speaking, all other sounds can be broken down into combinations of sine waves.
As you play higher notes on your keyboard, you’ll hear the oscillator at higher frequencies. Frequency is simply the amount of full cycles (see image above) the wave completes per second and it’s measured in hertz (Hz).
Operator has four oscillators labeled A, B, C, and D. This means that each oscillator can produce its own waveform independent of the other three (if you choose).
Notice that each oscillator section stretches horizontally and has parameter settings titled Coarse, Fine, and Fixed (All three relating to frequency of the oscillator), and then the Output Level for the Oscillator.
Oscillator A is selected and its Output Level is turned completely up, while the other three oscillator levels are turned down. Try adjusting the Coarse and Fine parameters for Oscillator A while playing a single key. You’ll notice that Coarse tunes the oscillator up or down by an octave, while Fine tunes the oscillator in smaller increments. Setting the fine parameter to the maximum amount (1000) will tune the oscillator up one octave. The button labeled Fixed will hold the oscillator at a fixed frequency no matter where you play on the keyboard. This is useful for drum synthesis.
Now set Oscillator A back to its default settings (pictured above). You can do this by selecting (clicking) each parameter and then hitting the delete button on your keyboard.
2. Operator Display
When an oscillator or section is selected, the operator display will show you more parameters in detail. It may look complicated at first, but it will make sense in no time.
In the image below, you can see that Sin is selected under the Wave parameter. This is the default setting, but you can select many other waveforms here.
Open the dropdown menu and select Triangle. Try playing the keyboard now. This is a Triangle Wave and its waveform looks as you might suspect:
It has a slightly brighter timbre than the Sine Wave because it has more harmonic overtones.
Now try listening to a Sawtooth Wave – Saw 64
And a Square Wave – Square 64
At higher frequencies, you might find that Saw and Square waves sound slightly similar. Try listening to them at lower frequencies. Set the keyboard range to C1-D2 (remember you can adjust this with the Z and X keys). The Status Bar display at the very bottom of Live will show you your range when you adjust it.
Low frequency square waves are often used as a starting place for thick bass sounds or sub bass.
Finally, try selecting and listening to White Noise. Noise isn’t a cyclical wave but it is a sound source that’s commonly used in synthesis.
White Noise Waveform:
You can use a device in Ableton called Spectrum to further grasp these waves and their harmonics. Check out the video on it below.