Dupertuis Electronique SA

Audiophile Circuits League Dual State VCF
Width 26 HP
Our Dual State Variable Filter is – on the surface – a very simple device, offering two powerful multimode VCFs, each able to operate in lowpass, bandpass, highpass, and notch mode. It really sounds beautiful, with a lovely liquid sound, and plenty of bass ‘oomph’. But our design makes it very versatile and powerful too.
At its simplest, it is a perfect mono filter: Ideal for creating incredibly fat kicks and other percussion – or thick basses, pads and leads. But when used as two parallel filters it can be used to apply extraordinary stereo effects to mono signals – from sweeping panoramas to ultra-wide characterful stereo-ising (using carefully applied notch filters on the left and right for example). And used in a serial configuration it yields stunning results, such as formant filtering, for organic vocal-like effects – on anything from pads to drums. Or simply running one 12dB filter into the next, creating a 24dB filter, but with the ability to alter the cutoff, resonance, and more… halfway through the process.
Naturally, the cutoff and resonance controls feature CV inputs, each with an attenuverter. And the individual filter types have their own outputs, all of which can be deployed simultaneously (with some additional options for Notch that are probably best left to the manual to explain!).
Finally, to simplify many (if not most) regular patching situations, all audio and CV inputs are normalised* from filter A to filter B.
In the end, the Dual State Variable VCF delivers everything you would expect and demand from a modular VCF, feature-wise, plus some well thought out routing, and a sound so creamy that you might well consider buying this module even if it was missing valuable features and was terribly designed.