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Table Of Contents
Creating Classic Waveforms in Ultrabeats Phase Oscillator Mode
The basic waveforms of classic analog synthesizers can be easily reproduced with the
phase oscillator: sine, rectangular, and sawtooth waves will result from different Slope,
Saturation, and Asym parameter value combinations.
For example, setting Slope and Saturation to their maximum values, and Asym to the
minimum value will result in a classic square wave. Setting Slope to −0.20, Saturation to
the minimum, and Asym to the maximum value, will result in a sawtooth wave. Setting
all three parameters to 0 values will cause the oscillator to produce a sine wave. See the
table below for an overview of the tonal qualities of each basic waveform.
CommentsBasic toneWaveform
Great for reed instruments, synth blips, bassesNasal soundingRectangular
Useful for basses, clarinets, and oboes. The pulse
width of (oscillator 2 and 3) square waveforms can
be smoothly scaled between 50% and the thinnest
of pulses.
Hollow and woody
sounding
Square
Useful for strings, pads, bass, and brass soundsWarm and evenSawtooth
Useful for flutes, padsSweet sounding, softer
than sawtooth
Triangle
The sine wave of Oscillator 1 can be
frequency-modulated by Oscillator 2. This kind of
frequency modulation forms the basis of
FM synthesis.
A pure toneSine
Using Ultrabeat’s FM (Frequency Modulation) Mode
Whereas the phase oscillator is well suited to simulations of analog waveforms and
analog-style sounds, FM mode is well suited to the creation of bell-like digital tones and
metallic sounds.
The principle of frequency modulation (FM) synthesis was developed in the late 1960s
and early 1970s by John Chowning. It was popularized by Yamahas range of
DX synthesizers in the 1980s. Ultrabeat can’t be compared with the DX series in the
discipline of pure FM synthesis, but it can certainly achieve some of the signature sounds
of these instruments.
How Frequency Modulation Works
Put very simply, the frequency of one signal generator (oscillator) is altered, or modulated,
by another signal generator. Positive, or higher, frequency values from the second
generator, known as themodulator, increase the frequency of the first generator, known
as thecarrier. Negative, or lower, frequency values from the second generator decrease
the frequency of the first.
257Chapter 11 Ultrabeat