How Does It Work?#

Diode LPF is a 4-pole diode ladder lowpass filter with an aggressive, gritty tone and a wide resonance range.

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Quick Overview#

• Diode LPF is a single-input, single-output analog-style lowpass filter.
• It exposes dedicated CV inputs for Cutoff and Q.
• The cutoff range is 20 Hz to 20000 Hz.
• Resonance ranges from 0.7072 to 25.
• This module does not include a dedicated drive control, so input level is part of the sound.

Inputs And Outputs#

Port	Type	What It Does
In	Audio	Signal sent into the diode ladder filter core.
Cut	CV	Modulates cutoff frequency.
Res	CV	Modulates resonance (Q).
Out	Audio	Filtered lowpass output.

Controls Reference#

Control	Range	Default	Behavior
Cutoff	20..20000 Hz	20000 Hz	Sets the lowpass cutoff frequency.
Q	0.7072..25	1	Sets resonance intensity around the cutoff point.

CV Behavior#

• Cut uses exponential frequency modulation, so equal voltage changes produce proportional pitch-like cutoff changes.
• Res adds linear modulation to the resonance control and is clamped to the module's valid Q range.
• Both modulation paths are smoothed in the DSP so fast automation does not step abruptly.

Character Notes#

• Compared with the transistor ladder filters, this one is the rougher option.
• It is still a lowpass design, but the resonance and nonlinear core give it a sharper edge.
• If you want more bite, raise the level feeding In; there is no separate drive knob on the panel.