CEM LOW PASS 29A
The
CEM LOW PASS 29A is a 24dB 4 pole low pass filter
based on the CEM 3328 filter IC. Usually we don't offer custom IC designs
but in this case the sound was worth it.
One of the main distinguishing capabilities of this filter
is the switchable volume compensation for high resonance settings. Most LPF
suffer from a 12dB drop in pass band
level at high resonance. The CEM 3328 IC has built-in provisions for overriding
this limitation. The result is a powerful sound even with high res.
Features:
Switchable
0dB or standard -12dB volume compensation
Input
The
filter input level is adjusted using the gain control attenuator. Moderate
gain settings provide the smoothest sound.
1V/Oct Input
Exponential converters track
linear voltage input at 1 volt per octave. This input is primarily used for
keyboard
tracking and pitch control of filter in self-oscillation mode.
CV Input 1
Control Voltage input with attenuator
to control the depth of frequency modulation.
When the knob is centered no modulation occurs. Positioning the knob to the
left of zero inverts the incoming voltage (negative) and to the right the
voltage is non-inverted (positive).
CV Input 2
Secondary Control Voltage input with attenuator.
CV inputs are used to control the filters cutoff point.
The most common
input signal would be from an envelope generator or LFO.
Resonance Control
This knob varies the height of the resonant peak at the cutoff frequency of
the filter.
Resonance CV
CV input to control the resonance amount with an attenuator
to control depth of modulation
Specifications:
Wide-range lowpass filter with variable-height
resonant peak at cutoff frequency.
4 pole response
24db/oct cutoff slope
Range:Continuously variable from 35Hz-20kHz
Input impedance:
50K ohms
Output impedance: 1k ohms
Control Sens: 1 volt per octave