MATTTECH NOTE: An earlier incarnation of this filter won a blind test of lowpass filters I put together a few years ago, against some pretty stiff competition. It was also a firm favourite here!
A deeper exploration of the Pittsburgh Modular Filter sound, the Binary Filter is a voltage controlled, analog, state variable filter based on the filter of the Lifeforms SV-1. The state variable topology was chosen because it allowed us to produce a very smooth and natural sounding filter, in addition to offering several other modes of operation, each with a unique sound and energy all their own.
There Is No Sweet Spot
The Filter defines the Jekyll and Hyde sound of Pittsburgh Modular. On the one hand, it offers a warm, organic sweep through the full frequency range. The lowpass filter is gummy and relaxed while the highpass is clean and defined. On the other hand, switching into unstable mode turns the Binary Filter into a howling beast capable of chunky walls of overdrive and noise. The goal was to produce a filter that does not have a single sweet spot. We worked to make every turn of a knob or flip of a switch offer something new and musically engaging.
Multiple filter responses are available simultaneously including lowpass, highpass, and bandpass.
Switch It Up
The stability switch selects between Stable and Unstable modes. Set to Stable, the LifeformsBinary Filter will not self oscillate, and operates as a clean, organic filter. Set to Unstable and without an incoming audio signal, theBinary Filter produces a high quality voltage controlled sine wave. Adjusting the Q while in Unstable mode modifies the shape of the waveform. Add an incoming audio signal to the Unstable mode and the output changes dramatically. At normal settings the incoming signal modulates the self oscillating filter to produce complex sounds. At more extreme settings, where the Binary Filter starts to struggle with self oscillation, the Q adds anything from ringing fuzz to heavy distortion to the incoming audio.
Power: 22mA @ +12v / 22mA @ -12v
AUDIO DEMOS (original Pittsburgh Filter – identical basic sound though):
Braids, Pittsburgh Filter + WMD Multimode VCA Patch by matttech offcuts
Lowpass Filter Shootout (simple sweeps) by Matttech Modular Demos
Lowpass Filter Shootout (extended tweaking) by Matttech Modular Demos