The DIODE FILTER 23A is a Lowpass filter inspired by the classic EMS diode ladder filter. In terms of sound it could be described as nasal compared with the Moog style ladder filter. A truly unique filter with plenty of character.


The filter input level is adjusted using the gain control attenuator.

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

Inputs: 50k ohms
Outputs: 560 ohms
Signal Output: 5 V p-p
CV input 0-5V