Ceremony

Nekyia Circuits 10HP
VCF FILTER RESONATOR VCA

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Dual analog 18dB/oct resonant twin-peak filter inspired by Rob Hordijk's TwinPeak. Morphs continuously from lowpass to twin-peak bandpass, crossfades two inputs (voltage-controlled), self-oscillates and pings cleanly, and adds cross-filter FM, per-input feedback and an output VCA.

Patch Ideas · 4

Twin-peak bell (1V/oct pinged voice)
Crank resonance into self-oscillation, ping with gates on Audio In A, and play pitch into Both CV. The two peaks track together as a dual-partial bell tuned by the Freq A/B interval.
Walkthrough
  1. Set Resonance to ~3 o'clock so both peaks just self-oscillate (you should hear a quiet sine pair).
  2. Set LP/BP to noon so both peaks are clearly audible.
  3. Set Freq A to noon and Freq B about a fifth above to hand-tune the bell interval.
  4. Set FM Mod fully CCW (off) and Feed A/B fully CCW for a clean pinged tone.
  5. Patch Sequencer (Pitch) >> Ceremony (Both CV) so 1V/oct transposes both peaks together.
  6. Patch Sequencer (Gate) >> Ceremony (Audio In A) to ping the resonators on each note.
  7. Patch Envelope >> Ceremony (VCA CV) so each ping has a short decay shape.
  8. Patch Ceremony (OUT) >> Output.
Signal out Ceremony OUT — plucky two-partial bell, pitched by Both CV.
Listen for A clean dual-tone bell that transposes in tune; widening the Freq A/B interval changes it from chime to gamelan-like clang. Add Feed A a hair for a darker, woodier strike.
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 4 connections. Modules: Ceremony, Sequencer, Envelope, Output. Signals: 1 audio, 1 cv, 1 pitch, 1 gate.CeremonySequencerEnvelopeOutputResonance: ~3 o'clock (just self-oscillating)LP/BP: noonFreq A: noonFreq B: noon + ~fifthFM Mod: offFeed A/B: offBoth CV1v/octAudio In AgateVCA CVcvOUTaudioPitch1v/octGategateOutcvInaudioaudiocvpitchgate
Crossfaded dual-source resonant filter
Run two oscillators into A and B, sweep the input crossfader with an LFO, and use the LP/BP morph as a tone control. The output glues both sources into one moving resonant image.
Walkthrough
  1. Set LP/BP to about 10 o'clock (mostly lowpass, a hint of peaks).
  2. Set Resonance to ~1 o'clock for a sung/vocal colour without self-oscillation.
  3. Set Feed A/B and FM Mod to off for a clean filter sound.
  4. Set Freq A around noon and Freq B a third above to colour the bandpass shoulder.
  5. Patch VCO A (Saw) -> Ceremony (Audio In A).
  6. Patch VCO B (Saw, detuned) -> Ceremony (Audio In B).
  7. Patch slow LFO >> Ceremony (XFade CV) so the mix slowly morphs A↔B.
  8. Patch keyboard / sequencer (Pitch) >> Ceremony (Both CV) so the filter tracks the played note.
  9. Patch Ceremony (OUT) >> VCA / Output.
Signal out Ceremony OUT — single filtered voice that morphs between the two oscillator timbres.
Listen for A vocal, slowly breathing dual-saw pad that drifts between source A and source B; raise resonance and Freq B for a more nasal/formant character.
▸ Show diagram
Patch diagramPatch diagram with 7 modules and 6 connections. Signals: 4 audio, 1 cv, 1 pitch.CeremonyVCO AVCO BSlow LFOKeysVCAOutputLP/BP: ~10 o'clockResonance: ~1 o'clockFreq A: noonFreq B: noon + thirdFeed A/B: offFM Mod: offAudio In AaudioAudio In BaudioXFade CVcvBoth CV1v/octOUTaudioSawaudioSawaudioOutcvPitch1v/octInaudioOutaudioInaudio11. detunedaudiocvpitch
Self-oscillating twin-peak drone
No external audio — just self-oscillation. Use a slow LFO on Both CV to drift the dyad and FM CV for slow inharmonic shimmer. The module becomes a pitched twin-peak drone voice.
Walkthrough
  1. Leave Audio In A and Audio In B unpatched.
  2. Set LP/BP to ~3 o'clock so both peaks are loud.
  3. Set Resonance to max so both peaks self-oscillate cleanly.
  4. Set Freq A and Freq B to taste — a wide interval (e.g. octave + fifth) gives a chord-like drone.
  5. Set FM Mod to ~10 o'clock for a touch of cross-FM shimmer.
  6. Patch slow LFO >> Ceremony (Both CV) to drift both peaks in unison.
  7. Patch second slow LFO >> Ceremony (FM CV) to wobble the inharmonic content.
  8. Open VCA CV with a fixed offset (or LFO) so the OUT stays audible.
  9. Patch Ceremony (OUT) >> Reverb -> Output.
Signal out Ceremony OUT — pitched dual-sine drone with slow harmonic motion.
Listen for A glassy, slowly tilting two-note drone; the two peaks beat against each other and the FM LFO adds shimmering sidebands. Push Resonance back a hair for breathier drift.
▸ Show diagram
Patch diagramPatch diagram with 6 modules and 5 connections. Modules: Ceremony, Slow LFO 1, Slow LFO 2, Offset, Reverb, Output. Signals: 2 audio, 3 cv.CeremonySlow LFO 1Slow LFO 2OffsetReverbOutputLP/BP: ~3 o'clockResonance: maxFreq A: lowFreq B: high (wide interval)FM Mod: ~10 o'clockFeed A/B: offBoth CVcvFM CVcvVCA CVcvOUTaudioOutcvOutcvOutcvInaudioOutaudioInaudioaudiocv
Feedback acid line
Feed a saw into A, raise Feed A and FM Mod, and sweep Freq A with an envelope. The audio-into-frequency feedback turns it from clean to vocal to gritty as you push it.
Walkthrough
  1. Set LP/BP to ~2 o'clock so the bandpass peaks dominate.
  2. Set Freq A to ~10 o'clock and Freq B to ~1 o'clock so they spread.
  3. Set Resonance to ~2 o'clock — hot but not self-oscillating yet.
  4. Set Feed A to ~1 o'clock so the input bites back into the cutoff.
  5. Set FM Mod to ~11 o'clock for cross-filter grit.
  6. Patch VCO (Saw) -> Ceremony (Audio In A).
  7. Patch Sequencer (Pitch) >> Ceremony (Both CV) for melodic 1V/oct tracking.
  8. Patch Envelope >> Ceremony (Freq A CV) (set Freq A CV attenuverter ~2 o'clock) for the classic acid wow.
  9. Patch Envelope >> Ceremony (VCA CV) so each note is shaped at the output.
  10. Patch Ceremony (OUT) -> Output.
Signal out Ceremony OUT — squelchy acid voice with biting envelope sweep.
Listen for A vocal, growling lead that overshoots into screaming territory at the top of each envelope; pull Feed A back for a cleaner 303 tone, push FM Mod CW for gnarly inharmonic spit.
▸ Show diagram
Patch diagramPatch diagram with 5 modules and 5 connections. Modules: Ceremony, VCO, Sequencer, Envelope, Output. Signals: 2 audio, 2 cv, 1 pitch.CeremonyVCOSequencerEnvelopeOutputLP/BP: ~2 o'clockFreq A: ~10 o'clockFreq B: ~1 o'clockResonance: ~2 o'clockFeed A: ~1 o'clockFM Mod: ~11 o'clockFreq A CV atten: ~2 o'clockAudio In AaudioBoth CV1v/octFreq A CVcvVCA CVcvOUTaudioSawaudioPitch1v/octOutcvInaudioaudiocvpitch

Behaviors

Continuous LP → twin-peak BP morph LP/BP control

Response morphs continuously from 18dB lowpass to a twin-peak bandpass shape with two independently tunable resonant peaks — no mode switching.

Interval-preserving frequency link Both CV (1V/oct)

Both CV transposes the pair of peaks together while keeping the interval set by Freq A vs Freq B intact, so chord-like dual resonances track pitch.

Cross-filter FM FM Mod knob / FM CV

Filter B's output is fed into Frequency A as FM, producing sideband colour that scales with resonance and FM depth.

Per-input feedback coloration Feed A / Feed B

Routing each audio input back into its own frequency control adds harmonics, vocal formants and screaming/ringing colours; pairs especially well with simple waves.

Self-oscillation & pinging high Resonance

At high resonance the two peaks self-oscillate as sine voices; trigs/clicks fed into Audio In A/B ping them for plucky, bell-like, dual-pitch percussion.

VC input crossfader / pre-VCA XFade CV

Crossfader between Audio In A/B is voltage-controlled; with one input unpatched it doubles as a pre-filter VCA on the other for tremolo or duck-into-resonance moves.

Output dynamics VCA VCA CV

Main output passes through a dedicated VCA so envelopes/LFOs shape level without an external VCA — useful for plucks, gating self-oscillation, etc.

Controls

Filter A Freq A Sets the first resonant peak frequency.
manual cutoff / resonance center
Filter B Freq B Sets the second resonant peak frequency.
manual cutoff / resonance center
Filter A CV Freq A CV atten Attenuverter for the Freq A CV input.
bipolar
Filter B CV Freq B CV atten Attenuverter for the Freq B CV input.
bipolar
Global frequency link Both Moves both peaks together while preserving the interval set by Freq A and Freq B.
Both CV input tracks 1V/oct
Response morph LP/BP Morphs the response continuously from 18dB lowpass toward twin-peak bandpass.
no mode switching, fully continuous
Global Resonance Raises Q on both peaks until the filter self-oscillates and pings cleanly.
voltage controlled · pings audio inputs at high settings
Filter A Feed A Routes Audio In A back into Freq A control for richer harmonic content.
audio-to-frequency feedback path
Filter B Feed B Routes Audio In B back into Freq B control for richer harmonic content.
audio-to-frequency feedback path
Cross-filter FM FM Mod Sets how much Filter B's output modulates Frequency A.
voltage controlled (FM CV)
Input crossfader XFade Blends Audio In A and Audio In B into the filter core. Acts as a VCA on either input when the other is unpatched.
voltage controlled

I/O

IN · 9

  • Audio In A audio AUDIO
    First audio input feeding the voltage-controlled crossfader.
  • Audio In B audio AUDIO
    Second audio input feeding the voltage-controlled crossfader.
  • XFade CV CV CV
    Voltage controls the input crossfade between A and B.
  • Freq A CV CV CV
    Attenuverted frequency CV for filter A.
  • Freq B CV CV CV
    Attenuverted frequency CV for filter B.
  • Both CV 1V/oct CV
    Tracks 1V/oct and shifts both peaks together while preserving the interval between Freq A and Freq B.
  • FM CV CV CV
    Controls the amount of cross-filter FM (Filter B output → Frequency A).
  • Resonance CV CV CV
    Voltage control for global resonance.
  • VCA CV CV CV
    Controls the output VCA on the main output.

OUT · 1

  • OUT audio AUDIO
    Main filtered output, level-controlled by the output VCA.