- CV 1 Amt.
- CV 2 Amt.
- varies the height of the resonant peak at the cutoff frequency of the filter.
- The filter input level is adjusted using the gain control attenuator. Moderate gain settings provide the smoothest sound but higher gain settings are better for high resonance sounds.
- Atten 1/2
- simple passive attenuators useful for limiting the amount of signal being passed to a modules inputs. They are available on this module to fill remaining space left by the filter
- CV 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 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.
- 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.
- Attenuator Output 1/2
- Attenuator Input 1/2
The 4075 Filter is a faithful recreation of the 24db low-pass filter found in late model Arp Odysseys.
The filter topology is almost identical to the Arp 4072 filter module found in later editions of the ARP 2600 synthesizer. This version has been modified to extend the frequency range from the original 16kHz up to 32kHz for improved fidelity.