This is the Eurorack version of my NGF 36dB VCF. I have brought out the 6dB, 12dB, 18dB, 24dB, 30dB and 36dB poles. You have two audio inputs for easy mixing sound sources. And CV inputs for linear TM, log TM, envelope, V/Oct tracking and emphasis. The exponential circuit is temperature compensated with KTY81-110. If the 12dB output is patched back to input 2 the filter can serve as a sine oscillator.
Specs and features
- 36dB voltage controlled low pass and high pass filter
- Two inputs for easy mixing
- 6dB, 12dB, 18dB, 24dB 30dB, 36dB output
- HP/LP switch
- Positive and negative ENV control with sign changer
- Temperature compensation with KTY81-110
- CV inputs for linear TM, log TM, envelope, V/Oct tracking and emphasis
- Usable as sine oscillator
- Runs on +/-12V and +/-15V (with minor resistor value changes for best performance)
- Power consumption around 60mA negative rail, 65mA positive rail
Straight forward design. Six state variable filter cells are connected together in series, The output of each filter cell is brought out. There are a lot descriptions of those state variable filters out there. I feel no need to add another one.