Mutable Instruments Blades — the 18HP dual multimode filter Émilie Gillet discontinued in 2022. No longer in production.

Build and provenance — please read: This is a DIY build, not a factory unit. The panel and knobs are genuine Mutable Instruments parts purchased directly from Émilie Gillet. The PCB was fabricated from her open-source design files, with SMD components machine-placed by JLCPCB. Through-hole assembly, testing and calibration done by hand.

What it does:

Two 12dB/oct filters with overdrive and wavefolding, covering everything from smooth and buttery to harsh and aggressive. Both sides are identical, with a routing control feeding the main output.

• Continuous response morphing — instead of picking a filter mode, you sweep continuously from low-pass through band-pass to high-pass, manually or under CV. When the filter self-oscillates with no input, that same control adjusts the phase of the sine wave.
• Cutoff from 8 Hz to 18 kHz, with attenuverted CV input plus unattenuated 1V/oct
• Resonance to self-oscillation — clean, constant-amplitude across the audio range and down into very low frequencies. Tracks CV sequences well enough to use as a stable oscillator.
• Drive — gain and distortion with its own CV input and offset; 0dB sits at 11 o'clock
• Response control — continuously variable between round soft-clipping and a two-stage wavefolder
• Routing knob — a dual crossfader. It sets how much of each filter reaches the MAIN output, and simultaneously how much of filter 1's input versus output feeds filter 2 (when filter 2's IN is unpatched). Morphs continuously from single to parallel to series.
• Shift button — links the two cutoffs, putting filter 2 under filter 1's control with adjustable offset
• Input level LED per filter

Patch one self-oscillating filter into the other for FM tones, or build a complete synth voice out of it. Also does DJ-style tilt filtering.

Specs:

• 18 HP, 25 mm deep
• Power: +12V 140mA / -12V 150mA (per the MI manual)
• Genuine Mutable Instruments panel