1 VCF Resonance :
2 Vary Control :
This control fades from LOW PASS response (fully counter clockwise) to NOTCH response
(control at 12 o’clock) and through to HIGH PASS response (fully clockwise). The resulting
filtering is routed to the VAR position of the VCF MODE switch (5).
In VARY mode the LP setting is 12dB slope, the NOTCH is 6dB slope and the HP 12dB slope
Manually sets the amount of Resonance (feedback) through the filter core. When a patch
cable is inserted into the RES CV jack (8) then this control acts as an attenuator for the
incoming RES CV level.
3 Freq CV Level :
This control is an attenuverter, which determines how much of the regular (or inverted)
Frequency CV signal patched to the FCV jack (10) is passed to the filter core to control the
cutoff frequency.
With this control at (approximately) centre position non of the Frequency CV signal will
be passed, however as this control is rotated clockwise then increasing amounts of FCV
signal will be passed to the filter core. Rotating the control anticlockwise from centre has
a similar effect, however the FCV signal is inverted.
For example, lets say that a +5V voltage is patched to the FCV Input jack (10). With this
control central then zero volts will be applied as a cutoff voltage, but when rotated fully
clo5V will then be passed to the filter as a cutoff voltage, thus “opening” the filter.
If the control is rotated fully anticlockwise then -5V will be applied to the filter as a cutoff
voltage, thus “closing” the filter.
4 VCF Frequency:
Manually sets the cutoff of the filter. Any external control voltages introduced from the
FCV Control, 1V/Oct and D-FCV Mix control are summed with this control setting, so in
this case it acts as a +/- offset control.
5 VCF MODE Switch : This selects the filter type that is routed to the OUT jack (7) and to the central mixing bus.
6 INPUT Level :
This is an attenuator that determines how much of the signal from the Input jack (11) is
passed to the filter input.
It also includes an overdrive function; if a regular Eurorack level audio signal (10V p/p) is
fed to the Input (11), then full signal level and unity gain corresponds to a setting of
around 8 on this control, and if it is rotated further clockwise then the output level will
still rise, but the filter core is driven into distortion and an “overdriven” sound is created.
7 OUTPUT :
8 VCF RES CV :
Patch a voltage or signal (modulation from an LFO or audio rate) to this input to exter-
nally control the filter Resonance. The amount of this signal passed to the filter core is
determined by the setting of the VCF RESONANCE control (1), which acts an an attenuator
when a patch cable is inserted into this jack socket.
The accepted signal range for this input is 0 to +5V. Negative signals will be ignored and
positive signals higher than +5V will be capped to +5V. Maximum permissible voltage to
this input is +/-12V.
Filter output. This is downstream of the VCF mode switch, so the filter type determined by
the MODE switch (LP, BP, HP or Vary) is routed to this jack. Please note that this output is
available simultaneously with other output jacks (12, 13 & 14). For example, if the MODE
switch is set to LP then this output will be low pass, however a low pass output will still
also be available from the LP OUT jack (12)
Note: This is the only way to get a Vary output from the front panel, as Vary does not have a
dedicated front panel output jack.
Description of individual filter controls
VCF1 and VCF 2 are identical and independent, these labels apply to both.
