A mono resonant filter with four modes and a contour that sweeps the cutoff every time you play a note. Put it after an oscillator, a drum loop or a guitar take and play it from a keyboard to make the tone move.
The idea
In a subtractive synth, nothing changes the sound as much per degree of rotation as the filter. Filter gives you the classic four shapes, plus an ADSR contour that opens and closes the cutoff in time with your playing. The contour is triggered by notes, so the audio passes through continuously while MIDI decides when each sweep starts and ends.
Controls
- Type picks which part of the spectrum survives: lowpass (the one that sounds like a synth), highpass, bandpass or notch.
- Resonance adds a peak at the cutoff. The default is smooth, with no peak; raise it for a vocal, ringing edge.
- Base and Depth set the contour's range. Base is where the cutoff rests, and Depth is how many octaves above it the contour can reach, up to eight.
- Attack, Decay, Sustain and Release shape the contour, with the usual ADSR editor.
- Static Cutoff is a fixed cutoff used when Depth is at zero, turning Filter into an ordinary tone control.
Any note starts the contour from the beginning, and any note release lets it fall, whatever the pitch or velocity. With Depth above zero and no note held, the cutoff rests at Base.
Getting started
Feed Filter an audio signal and play notes into it from your computer keyboard or a MIDI controller. Try Acid Sweep for a resonant squelch that falls back to a low base, Slow Open for pads that brighten gradually, Wah for a narrow band moving across the spectrum, Hollow Out for a highpass that drains the body away as the note holds, or Phaser Notch for slow colour in the mids. Play single notes at first to hear each sweep clearly; set Depth to zero to compare the fixed cutoff.
In a modular rack, Filter appears as a 24 HP panel with Audio Input, Contour MIDI and Audio Output sockets. Contour MIDI takes note events to trigger the contour; it is not a continuous control voltage input.
