These old school 24dB filters take you on a time travel into the 60ies, directly into the tape music studios!
Left-hand a high pass, right-hand a low pass; they can’t oscillate but growl and screech a lot. This dual filter is discrete, without opamp ICs and is based on the core of an old 100-series Buchla design.
Except for the filter type (high pass or lowpass) both filters have thesame features:
24dB/octave slope, big cutoff knob, voltage controlled resonance and two cutoff CV inputs with bipolar attenuators.
The highpass output is normalled to the lowpass input, allowing for easy creation of bandpass filters with adjustable width.