Audio Damage Phosphor - Manual (Page 12)

4. Low-Frequency Oscillators (LFOs)
Phosphor has two low-frequency oscillators (LFOs) that can be used to change, or modulate, several
parameters of the Primary and Secondary Oscillators, and the frequencies of the filters associated with the
delays.
The numeric LFO controls determine how fast the output of the LFO
varies over time. They operate either in units of frequency (Hertz, or
cycles per second), or in metrical units. The LFO’s rate can be set from
one cycle every 100 seconds (or 0.01 cycles per second, abbreviated
0.01 Hz) to 14 cycles every second (14 Hz). Click on the unit indicators
in the upper-right corner of the controls (i.e. the words “Hz” and
“sync”) to switch between the two modes.
The WAVESHAPE slider and WAVEFORM buttons work together to control how the LFO’s output varies over
time. The WAVEFORM buttons let you choose one of four waveforms, with sawtooth, pulse, sinusoidal, and
randomly determined shapes. The WAVESHAPE slider changes the basic waveform in different ways,
depending on which waveform is chosen with the WAVEFORM buttons.
 If the sawtooth wave is selected, and the WAVESHAPE slider is set to the middle of its range, the output
of the LFO rises and falls evenly between its lowest and highest values, creating a symmetric triangular
wave. If you move the WAVESHAPE slider to the left from its center, the LFO output rises more quickly
and falls more slowly. If you move the WAVESHAPE slider to the right, the LFO rises more slowly and falls
more quickly.
 If the pulse wave is selected, and the WAVESHAPE slider is set to the middle of its range, the output of
the LFO jumps between its lowest and highest values, staying for an equal period of time at both values.
If you move the WAVESHAPE slider to the left, the output stays at its highest value for a shorter period of
time. If you move the WAVESHAPE slider to the right, the output stays at lowest value for a shorter
period of time. In engineering terms, the WAVESHAPE slider varies the duty cycle of the rectangular
wave.
 If the sine wave is selected, and the WAVESHAPE slider is set to the middle of its range, the output of the
LFO varies smoothly between its lowest and highest values. The difference between a sine wave and a
triangle wave is that the triangle wave abruptly changes direction when it reaches its highest and lowest
values; whereas the sine wave gradually slows down, stops, and speeds up again when it changes