15 Audio Mix :
16 D-FCV Level :
The D-FCV control allows a second cutoff voltage to be sent to both VCF 1 and VCF 2, and
the D-FCV MIX control determines how this frequency CV is split between VCF 1 and VCF
2. This is a hugely powerful feature, as the cutoff frequency of both filters can be altered
using a single control, and varying amounts of CV directed to each filter to create
asymmetric sweeps.
An external control voltage can also be patched to the D-FCV jack, and in this case the
D-FCV control becomes an attenuator for the incoming external D-FCV signal.
The Audio Mix control cross-fades between the outputs of VCF 1 and VCF 2. It’s exact
function depends on the setting od the Dual/Cascade switch (18)
In manual mode, with the control fully anti-clockwise, only the output of VCF 1 will be
heard from the D-OUT output.
With the control (approximately) centred at 12 o’clock, an equal mix of the outputs of VCF
1 and VCF 2 will be heard at the D-OUT output.
With the control fully anti-clockwise, only the output of VCF 1 will be heard from the
D-OUT output.
External control of audio mixing is possible by applying a control voltage to the MIX CV
Input (22) and in this case the audio mix control becomes an attenuator for the incoming
CV voltage.
18 Dual / Cascade:
The Dual / Cascade switch determines how VCF 1 and VCF 2 are combined together in the
Mix Bus. This allows them to be can be connected in Dual (Parallel) or Cascade (Series)
DUAL - VCF 1 input is normalised to VCF 2 input, so that the same signal is presented to
both filters, and the AUDIO MIX control (15) cross fades between the outputs of VCF 1 and
VCF 2, and the resulting mix is sent to the D-OUT jack. It is also possible to connect a
different signal or waveform to VCF 2 Input (IN 2) and in this case the audio mix will
cross-fade between the individually filtered outputs of VCF 1 and VCF 2.
CASCADE - The output of VCF 1 (OUT-1) is connected to the input (IN 2) of VCF 2, so that
the Signal is first processed by VC 1, and then passed into VCF 2 for further treatment. The
Audio Mix control still cross-fades between VCF 1 and VCF 2, so in this case it cross fades
between one or two VCF’s.
For example, lets say both VCF’s are set to Low Pass mode, with equal control of the filter
cutoff on each. Now each filter has a cutoff slope of 12db/Octave, however because we
are treating the sound twice then this cutoff slope is doubled by the second filter, so we
can now have a SEM style filter with a four pole 24dB/ Octave slope! And we can freely
crossfade between the 12dB and 24dB variants!
17 Invert Switch:
This switch inverts the output of VCF2 with respect to VCF 1, so that when both filters are
combined in DUAL mode one filter output is inverted against the other, which causes a
different set of frequency and phase cancellations from non inverted. It is only effective
when the Dual/Cascade switch is set to the Dual position.
Description of Mixing Bus controls
Controls mixing and configuration of the two individual filters
