Eurorack Dual Multimode Filter

US Mutable Instruments releases Blades 10/12/20

Mutable Instruments has released Blades, a dual multimode filter in Eurorack format. It features a CV-controlled overdrive circuit capable of wavefolding and a clean 12dB/octave multimode filter, self-oscillating cleanly across the audio range. Here's the details direct from Mutable Instruments...

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.

Originally thought as a complex filter, Blades turns out to be capable of much more:

A dual distortion with spectral color control?

An oscillator mixer with crossfading, wavefolding, and enough filtering to clean up the mess?

A voice, using one filter as an oscillator, then distorting, folding it and filtering it with the second filter?

A complex oscillator capable of FM, PM and AM?

An essential overdrive circuit

A CV-controlled overdrive stage precedes each of the two filters.

Overdrive response continuously adjustable between soft-clipping and 2-stage wavefolding.

Two rich multimode filters

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.

Unique routing possibilities

Continuously variable (and CV-controlled) routing from single to parallel to series.

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.

Specifications

Fully analog, based on the V2164 quad VCA chip.

Frequency knob range: 8Hz to 18kHz.

Audio input impedance: 30k.

DC-coupled audio inputs.

Filter mode CV input impedance: 50k.

Other CV inputs impedance: 100k.

All CV inputs handle audio-rate modulations.