The Plague Bearer – A Quad Voltage-Controlled Resonant Bandpass Filter

Flight of Harmony’s Plague Bearer is a quad Voltage-Controlled Resonant Bandpass filter, designed with the goals of maximum signal alteration and maximum parameter controllability.

Flight of Harmony appears to subscribe to the Metasonix school of gear naming.

The Plague Bearer is currently sold out.


Each filter has controls for varying the high and low corner frequencies of the passband, as well as variable gain and an input attenuator. Each section of the Plague Bearer can be used as a filter, an oscillator, a noise generator, or even as a resonance oscillator!

Depending on the settings, the filter can be a lowpass, highpass, single-bandpass, or multiple-bandpass. Adjusting the resonance point can cause the filter to self-oscillate in many ways: By adjusting the controls to just below the point of oscillation, and then applying a pulse, square, or other abrupt-edged input signal waveform will “ring” the filter. A simple “click” on the input can give a percussive output sound – from bass drum to bell to a harsh metallic clang; Crank the controls up and this beast will scream like a banshee! The oscillation can be damped or continuous. Chain a couple in series and get accumulating feedback – the build-up can be slow, fast or instantaneous.

White Noise is easy to do – you don’t even need an input signal! Turn the input all the way down, and then slowly turn the gain up. You can adjust the “color” of the noise with the frequency controls. Daisy-chaining multiple filters can give a “comb” or multi-phase noise. About phase-shift characteristics: A single filter can give a STRONG chorus effect if so desired, useful as a sub-oscillator or just to “fatten” a sound.

The Plague Bearer’s patchbay is designed to fit the most patch options possible in the small space available. Each filter has four Input/Output (I/O) connections: High CV, Low CV, Signal In, and Signal Out. Each of these has two jacks, one 3.5mm phone jack for external signals to avoid floating grounds, and one 0.080” tip jack for internal patching between filters. Each pair is direct-connected as a multiple – NOT a summing node!

For maximum flexibility, the Plague Bearer can run off two 9V batteries or a 12V.A.C. wall wart (wall wart included with unit). The batteries are mounted externally in an unobtrusive location for ease of replacement. The power source is selected via the power switch.

Details at the Plague Bearer site.

via Matrix

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