Waldorf AFB 16 User Manual - page 34
Appendix
AFB16 User´s Manual
66
Clipping
Clipping is a sort of distortion that occurs when a signal
exceeds its maximum value. The curve of a clipped signal
is dependent of the system where the clipping takes place.
In the analog domain, clipping effectively limits the signal
to its maximum level. In the digital domain, clipping is
similar to a numerical overflow and so the polarity of the
signal’s part above the maximum level is negated.
Control Change (Controllers)
MIDI messages enable you to manipulate the response of
a sound generator to a significant degree.
This message essentially consists of two components:
• The Controller number, which defines the element to be
influenced. It can be between 0 and 120.
• The Controller value, which determines the extent of
the modification.
Controllers can be used for effects such as slowly swelling
vibrato, changing the stereo panorama position and
influencing filter frequency.
CV
CV is the abbreviation for control voltage. In analog
synthesizers, control voltages are used to control sound
parameters like pitch, cutoff frequency etc. E.g. to get a
tremolo effect, the output signal of a LFO must be routed
to the CV input of one or more oscillators.
Decay
"Decay" describes the descent rate of an envelope once
the Attack phase has reached its zenith and the envelope
drops to the level defined for the Sustain value.
Filter
A filter is a component that allows some of a signal's
frequencies to pass through it and dampens other
frequencies. The most important aspect of a filter is the
filter cutoff frequency. Filters generally come in four
categories: low pass, high pass, band pass, and band stop.
A low pass filter dampens all frequencies above the cutoff
frequency. A high pass filter in turn dampens the
frequencies below the cutoff. The band pass filter allows
only those frequencies around the cutoff frequency to
pass, all others are dampened. A band stop filter does just
the opposite, i.e. it dampens only the frequencies around
the cutoff frequency. The most common type is the low
pass filter.
Filter Cutoff Frequency
The filter cutoff frequency is a significant factor for filters.
A low pass filter dampens the portion of the signal that
lies above this frequency. Frequencies below this value
are allowed to pass through without being processed.