The Modulator Bank; The Envelope Follower; The Carrier Bank - Access Virus Rack User Manual

All you need is the internal synthesizer
of the Virus. It is also possible to process
external signals. The feature set of the
VIRUS includes 32 filter bands, shifting
the frequency's relation of modulator
and carrier, adjustable quality (Q-factor)
of the filter bands and much more.
The VIRUS's vocoder consists of different
sections which perform different tasks:
í

The Modulator Bank

This cascade of bandpass filters split the
frequency spectrum of the modulator
into slices, quite similar to the way a stu-
dio frequency analyser would.
í

The Envelope Follower

The level at the output of each bandbass
filter is measured by the modulator
bank. The resulting control signal can be
modified by an ATTACK and DECAY
parameter. These signals are no audio
signals, as they contain the envelope of
the signal being analysed.
í

The Carrier Bank

The signal is treated in a similar way to
the signal which passes the modulator
bank. In this case, the carrier signal is
split by the bandpass filters. Each band-
pass of the carrier bank corresponds to
one of the modulator bank. Usually,
both bandpasses use the same frequency
slice. Similar to a synthesizer's envelope,
the signal level being measured by the
envelope followers of the modulator, is
used to control the level of the carrier's
filter. Last, but not least, the individually
controlled signals of the carrier bank are
reunified to create the vocoder's output
sound.
ACCESS VIRUS RACK 163
Vocoder