User Manual

68 DeepMind 12 User Manual
The diagram below shows the results from high, medium and low settings of the
cut-o frequency when applied to the SAWTOOTH and SQUARE waveforms.
The VCF FREQ range is from 50.0 Hz to 20000.0 Hz. The default VCF FREQUENCY
setting is 20000.0 Hz(fully open).
The fader position, current value and stored value for the VCF FREQ fader is shown
on the PROG screen. There is also a visualization of the  lter curve as shown
below.
Note: The slope of the  lter will update depending on the use of a 2-pole or
4-pole con guration.
8.5.2 VCF RES FADER
The VCF RES fader controls the resonance of the  lter. When resonance is
increased the frequencies/harmonics/partials around the cut-o frequency are
emphasized. The resonance along with the  lter slope help de ne the character
of the  lter.
The DeepMind 12  lter is capable of being driven into self oscillation. Unlike many
other synthesizers, the synthesizer can guarantee an accurate pitch even when
the  lter resonance is pushed to (and past) the point where the  lter starts to
self-oscillate. When using this self-oscillating feature of the VCF as a sound
source, the VCF calibration ensures the correct response when playing the entire
scale of the keyboard. For more information please consult the section on
calibration later in this document.
The VCF RES range is from 0.0% to 100.0%. The default VCF RES setting is 0.0%.
The fader position, current value and stored value for the VCF RES fader is shown
on the PROG screen. There is also a visualization of the resonance as shown below
8.5.3 2-POLE SWITCH
This switch controls the con guration of poles used in the VCF.
The number of poles used in the  lter determines the angle of the  lters slope/
response curve.
The VCF uses 4-poles, but can be switched into 2-pole operation. If con gured for
4-pole operation the low-pass  lter rolls o signals above the cut-o frequency
at a rate of 24 dB/octave. When con gured for 2-pole operation the low-pass
 lter rolls o signals above the cut-o frequency at a rate of 12 dB/octave.
LEVEL (dB)
FREQUENCY (Hz)
HIGH
SAWTOOTH SQUARE
MED
LOW
VCF FREQUENCY
LEVEL (dB)
-3 dB
FREQUENCY (Hz)
LEVEL (dB)
-3 dB
FREQUENCY (Hz)
LEVEL (dB)
FREQUENCY (Hz)
LOW
SAWTOOTH SQUARE
MED
HIGH
VCF RESONANCE
LEVEL (dB)
FREQUENCY (Hz)
LEVEL (dB)
FREQUENCY (Hz)
ON=2P / OFF=4P