whimsical-raps/three-sisters
Three Sisters
THREE SISTERS links three filters (LOW, CENTRE, HIGH) for building spectral spaces. The three filters can be configured as lowpass, crossover, and highpass (crossover mode) or three bandpass filters (formant mode). Signals can be patched into individual filters or all three simultaneously, and outputs can be taken individually or as a mix.271
Visualization filter_response
Capabilities 3
- Multiband Filtermultiband-filter
- Three linked filter blocks (LOW, CENTRE, HIGH) with individual and global I/O, selectable crossover or formant mode.271
- Self-Oscillationself-oscillation
- All three filter blocks self-oscillate when QUALITY reaches approximately 3 o'clock, producing sine waves at the cutoff frequencies.271
- Vcfvcf
- FREQ CV input is V/oct; LOW block tracks accurately over ~5 octaves. SPAN and QUALITY also have CV inputs.271
Jacks 12 — 8 in / 4 out
| Name | Signal | Voltage | Description |
|---|---|---|---|
| Inputs (8) | |||
| ALL(IN) | audio | — | Patches a signal into all three filter blocks simultaneously.271 |
| CENTRE(IN) | audio | — | Direct signal input to the CENTRE filter block.271 |
| FM | mixed | — | Frequency modulation CV input, routed through an attenuverter before being added to FREQ. Accepts both control-rate and audio-rate modulation.271 |
| FREQ CV | cv | — | Volt-per-octave CV input for FREQ. A 1V increase doubles all cutoff frequencies. Accurately tracks V/oct over approximately 5 octaves.271 |
| HIGH(IN) | audio | — | Direct signal input to the HIGH filter block.271 |
| LOW(IN) | audio | — | Direct signal input to the LOW filter block.271 |
| QUALITY CV | cv | -5V to 5V | CV input for QUALITY/resonance; added to the QUALITY knob. With knob at noon, -5V to +5V sweeps from fully CCW to fully CW.271 |
| SPAN CV | cv | — | CV input for SPAN; added to the SPAN knob value. Controls the spread between LOW and HIGH cutoff frequencies.271 |
| Outputs (4) | |||
| ALL(OUT) | audio | — | Equal mix output of all three filter block signals.271 |
| CENTRE(OUT) | audio | — | Individual output from the CENTRE filter block.271 |
| HIGH(OUT) | audio | — | Individual output from the HIGH filter block.271 |
| LOW(OUT) | audio | — | Individual output from the LOW filter block.271 |
Parameters 5
| Name | Type | Range | Behavior |
|---|---|---|---|
| crossover/formant switch | switch | — | Selects between crossover mode (LOW=lowpass 24dB/oct, CENTRE=crossover 12dB/oct, HIGH=highpass 24dB/oct) and formant mode (all three are bandpass 12dB/oct).271 |
| FM attenuverter | knob | — | Attenuverter for the FM CV input before it is added to FREQ. Controls both attenuation and polarity of the FM signal.271 |
| FREQ | knob | — | Controls the cutoff frequencies of all three filter blocks simultaneously in the same direction. Works as a V/oct control when used with the CV input. The LOW filter block cutoff is FREQ minus SPAN; the HIGH block is FREQ plus SPAN; CENTRE in formant mode is solely FREQ.271 |
| QUALITY | knob | — | Clockwise from noon increases resonance; at approximately 3 o'clock the filters self-oscillate producing sine waves. Counterclockwise from noon blends in complementary (rejected) frequencies, creating notch filter responses and a dry/wet effect. At noon, resonance is at minimum and no rejected frequencies are mixed back in.271 |
| SPAN | knob | — | Pushes LOW and HIGH cutoffs in opposite directions around the FREQ centre-point. In crossover mode, also widens/narrows the CENTRE passband. In formant mode, CENTRE's bandpass cutoff is unaffected by SPAN.271 |
Firmware history 0 versions
No firmware history recorded.
References 2
- [271]
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[272]
Whimsical Raps Three Sisters product pageproduct_page● verified 2026-05-06