alm-busy-circuits/pip-filter
Pip Filter
A compact 4HP voltage-controlled 2-pole low-pass filter with resonance, a pingable trigger input, and a built-in VCA. Cutoff is controlled by a knob and dual CV inputs with an attenuverter; resonance reaches self-oscillation; a trigger input enables percussive plucked sounds; the VCA is normalled open for independent amplitude control.1041
Capabilities 3
- Pingable Filterpingable-filter
- Trigger input pings the resonant filter to produce percussive plucked tones; resonance must be near self-oscillation point for pinging to work.1041
- Vcfvcf
- 2-pole 12dB/oct low-pass filter with voltage-controlled cutoff and manual resonance that reaches self-oscillation.1041
- Voltage-Controlled Amplifiervca
- Built-in VCA normalled open; provides independent amplitude control of the filtered signal via a 0–5V CV input.1041
Jacks 6 (5 in / 1 out)
| Name | Signal | Voltage | Description |
|---|---|---|---|
| Inputs (5) | |||
| AUDIO IN | audio | — | 1041 |
| FREQ CV 1 | cv | 0V to 5V | First cutoff CV input with attenuverter for positive or negative scaling; expects 0–5V.1041 |
| FREQ CV 2 | cv | 0V to 8V | Second cutoff CV input with a wider 0–8V range; tracks 1V/oct very roughly and is suitable for pitch tracking.1041 |
| TRIG | trigger | — | Trigger or gate input that pings the filter; only fires on each rising edge to prevent double-pings with long gates.1041 |
| VCA CV | cv | 0V to 5V | Controls output volume independently from filter cutoff; normalled open so the VCA passes full signal when unpatched.1041 |
| Outputs (1) | |||
| AUDIO OUT | audio | — | Audio output after the filter and VCA stages.1041 |
Parameters 3
| Name | Type | Range | Behavior |
|---|---|---|---|
| Cutoff | knob | — | Sets the filter cutoff frequency; audio above the cutoff is attenuated at 12dB/octave. Dual CV inputs allow voltage control of cutoff.1041 |
| CV Attenuverter | knob | — | Scales the first cutoff CV input positively or negatively; allows the CV to increase or decrease the cutoff frequency.1041 |
| Resonance | knob | — | Sets the amount of resonance boost around the cutoff frequency. At maximum, the filter self-oscillates even without an input and approximately tracks V/Oct when a pitch signal is patched into the Freq input. Resonance must be set just below self-oscillation for pinging to work.1041 |
Firmware history 0 versions
No firmware history recorded.
References 2
- [1041]
-
[1042]
ALM Busy Circuits Pip Filter product pageproduct_page● verified 2026-05-29