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Chapter 22 ES2 267
Rate
This parameter defines the frequency or speed of the modulation. The value is
displayed in Hertz (Hz) beneath the slider.
Wave
This is where you select the desired LFO waveform. Check out the waveforms while a
modulation of Pitch123 is engaged and running. You should find the symbols quite self-
evident.
Triangular Wave
The triangular wave is well suited for vibrato effects.
Sawtooth Wave and Inverted Sawtooth
The sawtooth is well suited for helicopter and space gun sounds. Intense modulations
of the oscillator(s) frequencies with a negative (inverse) sawtooth wave leads to
bubbling and boiling, underwater sounds. Intense sawtooth modulations of lowpass
filters (such as Filter 2) create rhythmic effects.
Rectangular Waves
The rectangular waves make the LFO periodically switch between two values. The
upper rectangular wave switches between a positive value and zero. The lower wave
switches between a positive and a negative value set to the same amount above/
below zero.
Note: An interesting effect you may wish to try out is achieved by modulating Pitch123
with a suitable modulation intensity that leads to an interval of a fifth. Choose the
upper rectangular wave to do so.
Sample & Hold
The two lower waveform settings of the LFO’s output random values. A random value is
selected at regular intervals, defined by the LFO rate. The upper waveform delivers
exact steps of randomization. At its lower setting, the random wave is smoothed out,
resulting in fluid changes to values.
Note: A random modulation of Pitch123 leads to the effect commonly referred to as a
random pitch pattern generator or sample and hold. Check out very high notes, at very
high rates and high intensities—you’ll recognize this well-known effect from hundreds
of science fiction movies!
Note: The term Sample & Hold (abbreviation—S & H) refers to the procedure of taking
samples from a noise signal at regular intervals. The voltage values of these samples are
then held until the next sample is taken. When converting analog audio signals into
digital signals, a similar procedure takes place: Samples of the voltage of the analog
audio signal are taken at the rate of the sampling frequency.