- In 1
- controls the level of input 1
- In 2
- controls the level of input 2
- In 3
- controls the level of input 3
- controls the cutoff frequency of the filters
- controls the resonance of the filters
- CV 1 Depth
- controls how much CV 1 influences the filter cutoff frequency
- CV 2 Depth
- controls how much CV 2 influences the filter cutoff frequency
- Audio input 1
- Audio input 2
- Audio input 3
- Voltage control of the filter's cutoff frequency at a fixed 1V/Octave. Normally used to track the keyboard.
- extra CV inputs to control the filter's cutoff frequency.
- High-pass filter output
- Band-pass filter output
- Low-pass filter output
- Notch filter output
This is a two pole multimode filter capable of high pass, low pass, band pass and notch output modes. All four outputs are available simultaneously. This very popular Oakley design is based around the classic two pole state variable filter as used in a variety of vintage synths including Oberheim SEM and OB-Sx. The Oakley SVF uses high quality linearised OTA ICs to create a clean, low noise filter. The filter will oscillate over most of the audio band and is temperature compensated.
The design is intended to fit into a 2U wide panel with seven control pots. Three audio inputs are provided each with its own attenuator. Three CVs can control the cut-off of the filter. One is fixed at 1V/octave, the other two have input attenuators. CV2 features a reversible type attenuator with inverting/non-inverting properties.