Index 3Interpole Contents
Structure and Overview A ”voltage controlled” amplifier module
(VCA) follows the filter. The amplifier is
also controlled by the envelope and LFO.
Envelope control can be switched off so
that the LFO/VCA can serve as a tremolo
orautopanner.
Thanks to the Circuit Modeling process,
theaudio isfaithfully renderedandfree of
aliasing.Thosefamiliar with aliasingknow
thatitproduces unpleasant andunnatural
sounding analog signals. Interpole’s
variousmodulationeffectsandtheresulting
audio quality profit from this unique
process. Often various distortions or
sidebands fill out the full range of the
spectrum as a result of heavy or wild
modulations (such as frequency
modulation). Alias-free rendition is
absolutely necessary for producing such
spectra.Afterworkingforawhile with new
sounds you will come to appreciate this
characteristic.
Nolessimportantthantheenvelopestage
is the LFO. It features six modulation
waveforms, and synchronization to MIDI
clock if desired. Individually adjustable
intensitiesareavailableforfilterfrequency
and amplitude modulation. In
link
mode,
the LFO switches the signal from the first
channel to the second, with optional
modulation inversion on the second
channel, to produce stereo-filter autopan
effects. By restarting the LFO with MIDI
triggersorbymodulatingtheLFOratewith
anenvelope,theLFOmodulationbecomes
even more complex and lively.
But it is the filter that performs the most
important task: the actual signal
processing.Inadditiontothestandardcut-
off and resonance parameters, the filter
also provides a
Drive
parameter to
introduce distortion that produces effects
from gentle saturation to heavy distortion
with strong resonance—everything you
could ask for in a filter. The filter is
controlledbytheenvelopeand/ortheLFO.
Withappropriateconfiguration allkindsof
exciting stereo filter effects can be
produced.
Interpole is a stereo effect consisting of
two identical sections, left and right, for
the processing of any audio signal. Each
section consists of an envelope follower
or
ADSR envelope generator, an LFO, a
lowpassfilter,andaVCA.Thetwosections
canoperateindependentlyorin tandem in
link mode so that the filter can be used to
process either two mono signals or one
stereosignal.
Interpoleismorethanasimpleeffect:think
of it as a synthesizer in which the
oscillatorsarereplacedbyexternalsignals.
Theenvelopes and LFOscontrolthe filter
and theVCA just as in a synthesizer.
OneofInterpole’smostimportantfeatures
is the envelope section. The envelope
section can operate in one of two modes:
”Env” or ”Gate”. In Env mode the section
implements an envelope follower. Gate
modeimplementsanattack-decay-sustain-
release(ADSR)envelopegeneratorwhich
canbetriggeredbyaThresholdorviaMIDI.
The envelope can modulate filter
frequency,amplitude,and LFOrate.
