Oscillators – The Carriers

Knowing about the Envelope Generator is a must before you get to Oscillators. It’s true that oscillators generate the sound, but EG contours it all to be the sound you wish to design by controlling the various parameters available on a synth. Exclusively, FM Synths use the term “Operator” and that is entirely because operators have an adaptive function of switching between Modulators and Carriers as and when required by the user.

A carrier is basically an active oscillator with a waveform that “carries” the sound to the speaker. So when you press a note on the synth, it is the carrier carrying the sound and the assigned waveform on the active oscillator can be heard. So, what is an oscillator? That got me in a tricky spot. Bear with me for a bit, an oscillator is a sound source having different waveforms available to generate the sound. Since the waveforms are accessible within an oscillator, we can increase the number of oscillators on a synth. That provides us with the liberty of mixing the characteristics of different waveforms as well as changing their basic pitch to taste.

?The available waveforms depend on the type of synth you are using. For example, most subtractive synths would use waveforms consisting of a rich and fuller sound. An FM synth on the other hand would only house operators capable of producing a sine wave (more on this in following articles). In order to know the sounds, one must know the waveforms. Let’s begin!

1) Sine: Sine is a basic waveform. It is the purest waveform with no harmonics or richness in its sound texture. You may not find it on a subtractive synth since closing the filter would reduce/cut all the harmonics and you’d be left with a fundamental tone and that is close enough to a sine wave. It is mostly used as a sub-bass sound and could also mimic telephones if mixed with other slightly dissonant sine oscillators. There are many more uses of this waveform, explore this waveform thoroughly to find them for yourself.

2) Triangle: This waveform is made up of odd harmonics added to a sine wave. The wave when viewed on an oscilloscope looks like a triangle, hence the name. It is mostly used as an electronic flute sound due to the mellow nature of its harmonics.

3) Saw: Saw is the richest waveform consisting of all harmonics. It is a sound mainly used for leads and is found easily on every subtractive synth. The most common sound is the super saw which is achieved by adding a chorus effect to the oscillator or by mixing detuned oscillators to give it a fuller stereo sound.

4) Square: Square and Triangle waveforms have their harmonics in common although the amplitude of the harmonics is found to be louder in square than in triangle. Square waveforms have a video game feel to it and can be found used in most retro tracks as a lead, bass or even a chiptune sound. The square wave is the second most versatile sound since it incorporates a stable fifth note as its first harmonic.

5) Pulse Width: A pulse width waveform is a skewed square waveform. It may not be available on all subtractive synths. It sounds a bit different than a standard square wave and has a rich palette of sound which I have seen used in one of my favourite lead patches from the plugin called "PoiZone" by Image-Line.

6) White Noise: Yes! Surprisingly, noise is a type of sound available in many synths. It consists of all harmonics having full amplitude. Don’t be fooled, noise is one of the best texture adding ingredients available out there. It can be used to create percussive sounds as well as SFX (Special Effects). When used correctly, a person can add a good amount of texture and quality to their sounds.

With these basic waveforms you can start to experiment and figure out which waveforms work for you. They are the key to making a sound your own, perhaps the best fundamental that you could build on. ?This is exactly where the fun with synthesizers begins.