Chippmann CS-8 VCF1E, Руководство пользователя, Страница: 15 / 28

CS-8 Series VCF1E Rev1.2, Feb. 2018
-13-
Fig. 3 shows the structure of the filter. In the following piece by piece every
parts will be described and as the case may be exemplified with graphics.
Input
This section includes the
jack 9 (Input) and the controller 1 (Input) . The input
signal to be processed by the VCF1E flows from
jack 9,
capacitively decoupled,
to the Cont. 1 where it is attenuated between 0 (-
∞
db) and 1 (0 db). To obtain
a signal gain of 1 (without resonance) at the signal output
Out
(at
Gain
= 0 db),
the
Cont. 1
has to be set to full CW.
Hint: This filter is, btw. as all CS-8 filters, constructed in that way, that it shows
lowest harmonic distortions and cleanest sound at studio level input (0.775
V
RMS
or ca. 1-2 V
pp
). The input amplitude has a BIG influence of the sound, the
resonance and the dynamic behavior of the filter.
Frequency
This section includes the
controller 4 ( Freq ) , the jack 10 ( CV In ) , 11 ( 1V/Oct. )
and the controller 2 ( CV-Depth ) . Frequency means that one, where the filter at
high resonance (see below) oscillates with. At same time this is the frequency
where the roll-off starts at low-, or high-passes or center-frequency for band-
passes, resp.. The controller
Freq allows a range from 2 Hz to 40 kHz. A control
voltage (CV) at jack 10 will be attenuated between 0 - 1 via the controller CV-
Depth . At full CW the sensitivity is about 1.9 octaves/Volt. A CV at jack 10 is
weighted with 1 octave/Volt. This input is calibrated.
Hint: In phaser mode (s. below) are existing two resonance frequencies, which
are located left and right from the roll-off frequency in the classical filter mode.
Resonance
This includes the
controller 3 (Reso) and the jack 13 (CV-Res) . The resonance
is the self-resonance of the filter which comes into being when the filter
output will be feed back to the filter input in a controlled way. The tendency to
self-oscillation rises up from left to right of the controller
Reso starting from
none to self-oscillation at about 3 o'clock (sine symbol). A CV from 0 V to +5 V
at
jack 13 causes the same effect as the controller Reso from left to right. At +4
V (
Reso
-position = 0) the filter starts to oscillate. Input signals will be amplified
around the resonance frequency as illustrated in Fig. 4.