A valve-driven state-variable filter in the tradition of the rackmount club filter.
Inlets
Audio
2
Outlets
Audio
2
A drive stage feeds a resonant filter whose HI, BAND and LO buttons combine rather than exclude each other: HI with LO is a notch to sweep for phasing, all three together is an all-pass that Resonance makes dramatic, and none selected passes the signal clean. An envelope follower and a triangle or square sweep can both push the cutoff, or the envelope can be sent into the drive instead. Every switch is soft, so the buttons can be ridden in a performance without clicks. Cord it after a Rhizome, a Drums organism or a whole Mixer, and cord an LFO or a Follower onto Frequency for more shapes than the built-in sweeps give.
Parameters
EnvFollow
How far the input's loudness opens the cutoff. Zero leaves the filter static.
EnvDecay
Fast or Slow release for the envelope once the input drops.
Drive
The valve stage. It adds warmth first, then soft clipping, then hard clipping as you push, with make-up gain so the level stays put.
EnvToDrive
Sends the envelope into Drive instead of the cutoff, so loud passages distort more.
LfoSpeed
Sweep rate from 0.2 Hz to 10 kHz. Past a few hundred hertz the sweep itself becomes a tone.
LfoWave
Triangle glides between the ends of the sweep. Square jumps between them.
LfoSync
Locks the sweep to the transport instead of LfoSpeed.
LfoBeats
The length of one synced sweep in beats, so 4 is a bar of four.
LfoDepth
How far the sweep pushes the cutoff, up to a few octaves each way.
Resonance
From a gentle roll-off to a synth peak. It eases back on its own at high input levels and low cutoffs so full sweeps stay speaker-safe.
HiPass
Adds the high-pass band to the output.
BandPass
Adds the band-pass band to the output.
LoPass
Adds the low-pass band to the output.
Frequency
The cutoff, 20 Hz to 20 kHz. The big sweep.
FilterOn
Switches the filter in or out. Off is a clean straight wire.
Mono
Runs both channel filters in series from the left input for a 24 dB slope and doubled resonance, feeding both outputs.
MixInvert
Outputs the dry signal minus the filtered one, for cancellation effects that sit well before a delay or reverb.
Recipe
Synced sweep
LoPass on, Resonance 6, Drive 3, Frequency 400. LfoSync on, LfoBeats 4, LfoWave Triangle, LfoDepth 6. Cord a Drums organism in and the cutoff opens and closes once a bar in time with the transport.
