Dual multimode filter

A CV-controlled overdrive circuit capable of wavefolding. A clean 12dB/octave multimode filter self-oscillating cleanly across the audio range. Times two. And this could have stopped here. What sets Blades apart is that options commonly presented as multiple choices (low-pass or high-pass? serial or parallel?) are presented here as a continuum, ready to be explored at the twist of a knob or with a CV. The filter response is continuously variable between low-pass, band-pass and high-pass, and delivers intermediate shelving responses, for more nuanced spectral coloring. A dual crossfader circuit allows the routing between the two filters to smoothly vary from single to parallel to series.

Features
• A CV-controlled overdrive stage precedes each of the two filters. Overdrive response continuously adjustable between soft-clipping and 2-stage wavefolding
• Clean 2-pole (12dB/octave) state-variable design
• CV-controlled filter response, continuously variable between low-pass, band-pass and high-pass.
• CV inputs with attenuverters for cutoff and resonance.
• Unattenuated frequency CV input, calibrated for 1V/Oct tracking.
• Clean self-oscillation across the audio range, extending into very low frequencies, with constant amplitude.
• Modulating the filter response is akin to modulating the phase of the self-oscillation tone.
• With a signal patched into filter 2’s audio input, the routing knob and CV act as a crossfader.
• Filter 2’s cutoff can be set relatively to filter 1’s cutoff.
• Fully analog, based on the V2164 quad VCA chip
• DC-coupled audio inputs
• All CV inputs handle audio-rate modulations.

In the Box
• The module itself
• Eurorack Power Cable