User's Manual

5.5. About waveforms
Each kind of waveform has its own unique harmonic content. Understanding the difference
between them will help you know which one to select for your purpose.
A sine wave, such as the one in VCO-2, has only a single fundamental frequency, with
no harmonic overtones at all (although that's an ideal that real-world synthesizers don't
achieve perfectly). A sine wave's timbre doesn't change when it's filtered; it can only be
made louder or softer. All other periodic waveforms are made up of combinations of sine
waves of varying frequencies and levels. As a tone, it provides body; as a modulator, it's the
most common waveform for vibrato.
A square wave has a very rich series of overtones to the fundamental, theoretically infinite,
so there’s lots to play with. But it emphasizes the odd-numbered harmonics (third, fifth,
seventh and so on), so it has an aggressive edge to it. If a square wave sounds distorted to
you, there’s good reason. “Clipping” distortion is what happens when you overdrive a signal
to the point where the tops and bottoms of the waveform flatten out. The harder you clip a
sine wave, the more it looks and sounds like a square wave.
A triangle wave has a strong fundamental tone with only odd-numbered harmonics, no
even (octave) harmonics.
A sawtooth wave has a harmonic series with both even and odd harmonics in relative
balance, so sweeping a filter across it gives a smooth sweep.

♪: To hear what all this talk about harmonics and overtones means musically, try this experiment
with the JUP-8 V4:
1. Start with the "Default" preset.
2. Turn the SOURCE MIX knob all the way to VCO-1.
3. Push the VCF RES control all the way up.
4. Play a note on the keyboard and pull the VCF CUT control down slowly. You'll hear the filter sweep
through the harmonics of the triangle wave.
5. Set the VCO-1 WAVE to the other waveforms and do the same thing. Notice the differences in the
harmonics that the filter resonance emphasizes as you change the CUT frequency.
5.5.1. The RECTANGLE wave and PULSE WIDTH Modulation (PWM)
The rectangle wave is a relative of the square wave. It occupies the third position of the
WAVE switches in VCO-1 and VCO-2. The rectangle waveform is unique because it can
generate different series of overtones, depending on the setting of the PWM section of the
VCO MODULATOR. A rectangle wave (also called a pulse wave) is a signal that switches
between positive and negative values very quickly, with a "plateau" that depends on the
pulse width setting.
A wave that switches abruptly between positive and negative values, with no stops to rest
at zero in-between, is a square wave; it contains the loudest fundamental. When the PWM
FADER is at zero, a rectangle wave sounds identical to a square wave (4th position of the
WAVE switch in VCO-1). In this position, the fundamental frequency is dominant.
35 Arturia - User Manual Jup-8 V4 - VCOs