Voltage Controlled Filter Block - Panda-Audio Future Impact I User Manual

Voltage Controlled Filter Block

The Voltage Controlled Filter (VCF) Block consists of three parts, an audio
mixer, the filter cutoff modulation part, and the filter parameters.
AUDIO BASS / DIST / AR.DIST / SYNTH / NOISE (0..127): This is a four channel
mixer at the input of the VCF. The first channel is the direct bass guitar sound
itself. The output of the Harmonizer / Distortion Block is connected to the
second input channel. The fourth channel is the synthesizer sound, and the
fifth is the noise generator. The third channel has a very special function,
which is coupled with the function of the fourth channel, the synthesizer
sound.
As we discussed earlier, the synthesizer sound is passing through the VCA. This
means, if you adjust a significant attack time, then the note will start with a
delay after picking. The AR.DIST channel consists of the distorted sound (like
the second channel) but processed through another VCA which is controlled by
the inverse envelope of the synthesizer VCA. This way, if you adjust roughly
same loudness levels for AR.DIST and SYNTH, and adjust a significant attack
time then you will get a sound which starts as a sound with Harmonizer/
Distortion, and fades through to a synthesizer sound. Although relatively few
of the demo sounds use this feature, this can be used to cover perfectly an
eventual tracking error/delay of the synthesizer sound.
MODULATION FRQ VINTAGE (-1..80) / FRQ NEW (36..122): These are two
controllers for the same function, the basic frequency of the VCF. While the
Deep Impact had an inaccurate approximation of the necessary exponential
filter control characteristic, The Future Impact has a perfect implementation.
However, in order to emulate the Deep Impact sounds it was necessary to
emulate the imperfection of the filter. Therefore, in the Deep Impact emula-
tion sounds (the first 9 of the default set) FRQ VINTAGE is used to set the filter
frequency, and the setting of FRQ NEW is irrelevant. If FRQ VINTAGE is set to
-1, then FRQ NEW becomes active. The scaling of these parameters is roughly
10 units/octave for FRQ VINTAGE, and the number on the slider of FRQ NEW is
exactly the MIDI number of the filter frequency.
MODULATION ENVELOPE FOLLOWER (0..127) / AD(0..127) / PITCH FOLLOW
(0..1): The frequency of the filter can be modulated dynamically from different
sources. The Envelope Follower signal is following exactly the loudness
envelope of the bass guitar, so a portion of the control from this source can
give a very dynamic modulation to the sound. The AD modulation is the VCF
Envelope Generator signal, with adjustable attack and decay times. Pitch
Follow can be set to either 0 or 1. If it is set to 0, the filter frequency is steady,
independent from the bass guitar signal. If it is 1, the filter frequency is
accurately tracking the bass guitar signal. This can be used for many purposes,
among others to generate whistling sounds with very sharp filter adjustment.
ND
MODULATION FRQ 2 (0..24): FI has not only one VCF, but two of them. They
are connected in parallel. The second one has a single adjustable parameter,
ND
FRQ 2 . The resonance (Q) parameter is the same as the first one, the filter is
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