CS-8 Series VCF-02

Schippmann 24HP
VCF FILTER PHASER DISTORTION

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Fully analog multimode filter with 121 selectable filter shapes built by combining five filter taps (ALL, BP6, LP12, BP18, LP24) with per-tap sign inversion. Unique Emph, 2nd Harm, and Drop parameters.

Patch Ideas · 10

★ Classic 24dB ladder-style LP
LP24 green only · all others off · Reso ~6 Emph 0.5 · Drop -3dB to compensate bass loss · envelope into CV1 · sounds like a Moog ladder but with Schippmann transparency
▸ Show diagram
Patch diagramPatch diagram with 5 modules and 4 connections. Modules: VCF-02, VCO, Envelope, VCA, Output. Signals: 3 audio, 1 cv.VCF-02VCOEnvelopeVCAOutputLP24: greenReso: 6Emph: 0.5Drop: -3dBCV1: 1 oct/VInput1audioCV1cvOutputaudioSawaudioOutcvInaudioOutaudioInaudioaudiocv
Super notch for formant shaping
Preset A6: ALL blue · LP24 red · BP18 green · LP12 green · BP6 red · deep 4-pole-style notch · modulate Freq for vocal-formant sweeps
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: VCF-02, VCO, LFO, Output. Signals: 2 audio, 1 cv.VCF-02VCOLFOOutputALL: blue onLP24: redBP18: greenLP12: greenBP6: redReso: 4Input1audioCV1cvOutputaudioSawaudioTricvInaudioaudiocv
★ Whisper self-oscillation behind mix
Emph 0.1 · Reso 10 · 1V/Oct from sequencer · self-oscillating sine sits quietly in the mix as a ghost melody under a dry lead · unique Emph/Reso split makes this possible
▸ Show diagram
Patch diagramPatch diagram with 3 modules and 2 connections. Modules: VCF-02, Sequencer, Mixer. Signals: 1 audio, 1 pitch.VCF-02SequencerMixerLP24: greenReso: 10 (self-osc)Emph: 0.1 (whisper)1 V/Oct1v/octOutputaudioPitch1v/octIn 2audioaudiopitch
Two-stage phaser
Preset A9: ALL blue · LP24 green · BP18 red · LP12 red · BP6 red · audio rate LFO into CV2 with 180 invert · rich phaser tone
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: VCF-02, VCO, LFO, Output. Signals: 2 audio, 1 cv.VCF-02VCOLFOOutputALL: blue onLP24: greenBP18: redLP12: redBP6: redReso: 2CV2 phase: 180Input1audioCV2cvOutputaudioSawaudioTricvInaudioaudiocv
★ CV-morphed filter type
Sequencer gate/CV into LP12 and LP24 jacks (overrides buttons) · different steps yield different filter shapes per step · the filter becomes a filter-type sequencer
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 4 connections. Modules: VCF-02, Sequencer, VCO, Output. Signals: 2 audio, 2 cv.VCF-02SequencerVCOOutputALL: blue onInput1audioLP12cvLP24cvOutputaudioCV 1cvCV 2cvSawaudioInaudio121. steps through off/+/-2. independent morphaudiocv
Audio-rate resonance FM
LP24 green · Reso ~7 · VCO sine into Reso CV via CV-Res at ~50% · resonance wobbles at audio rate generating FM-like sidebands around the resonance peak
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: VCF-02, VCO A, VCO B, Output. Signals: 2 audio, 1 cv.VCF-02VCO AVCO BOutputLP24: greenReso: 7CV-Res: ~50%Input1audioResocvOutputaudioSawaudioTrianglecvInaudio11. audio-rate resonanceaudiocv
Warm 2nd-harm bass
LP12 green · LP24 green (both LP same sign = +6dB bass boost) · 2nd Harm on · Drop -6dB · saturated, warm, deep bass where the Schippmann's 2nd harmonic distortion sits perfectly
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: VCF-02, VCO, Envelope, Output. Signals: 2 audio, 1 cv.VCF-02VCOEnvelopeOutputLP12: greenLP24: green2nd Harm: ONDrop: -6dBReso: 5Input1audioCV1cvOutputaudioSawaudioOutcvInaudioaudiocv
Phase-cancel dual CV sweep
CV1 knob ~2 oct/V · CV2 knob same · CV2 phase switch 180 · same modulator into both · the two opposing CVs partially cancel to yield a subtle filter nudge without full sweep range
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 4 connections. Modules: VCF-02, LFO, VCO, Output. Signals: 2 audio, 2 cv.VCF-02LFOVCOOutputCV1: 2 oct/V · phase 0CV2: 2 oct/V · phase 180Input1audioCV1cvCV2cvOutputaudioTricvSawaudioInaudio11. phase-inverted, partial cancelaudiocv
Band-pass triple-RC wah
Preset B3: BP6 on · LP12 red · BP18 off · LP24 green · narrow 6/12 band-pass · slow envelope follower on cutoff for wah motion
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: VCF-02, VCO, Envelope Follower, Output. Signals: 2 audio, 1 cv.VCF-02VCOEnvelope FollowerOutputBP6: greenLP12: redLP24: greenReso: 5Input1audioCV1cvOutputaudioSawaudioOutcvInaudioaudiocv
HP from all-pass minus LP
ALL blue on · LP12 red · BP6 and BP18 off · clean 6dB HP preset H1 · resonance emphasizes the corner with no bass build-up · great for removing rumble on pads while keeping motion
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: VCF-02, VCO, Envelope, Output. Signals: 2 audio, 1 cv.VCF-02VCOEnvelopeOutputALL: blue onLP12: redReso: 4Input1audioCV1cvOutputaudioSawaudioOutcvInaudioaudiocv

Behaviors

121 filter shapes by tap summing combining ALL/BP6/LP12/BP18/LP24 button states

Each tap can be off, added (+, green), or subtracted (-, red). ALL is on/off. Sum of signs produces 27 low-pass, 18 high-pass, 13 band-pass, and 63 all-pass/notch/phaser shapes. Classic Moog-style 24dB LP is +LP24; high-pass is ALL on + LP12 red. The filter types chart in the manual lists labeled presets (T1-T9, B1-B5, H1-H5, A1-A21).

Emph decoupled from Reso turning Emph independently of Reso

Unique to this filter: Emph sets the AMPLITUDE of self-oscillation, not the threshold. Low Emph = self-osc barely audible, high Emph = huge self-osc. Reso sets Q. Combination allows whispered singing resonance behind a dry signal — impossible on standard filters.

Drop compensates LP bass loss turning Drop up on LP modes with resonance

Recovers low-frequency gain that typical LP filters lose as resonance rises. -3 to -6dB is a good compromise between compensation and overload. Drop only operates in low-pass shapes (yellow on-LED indicates). Pushing Drop too hard saturates the filter input for optional overdrive.

2nd harmonic warmth 2nd Harm button active or CV > +3V

Adds soft even-harmonic distortion that emphasizes 2nd harmonic (octave up). Effect deepens with resonance level. Produces a 'warm' coloration distinct from the ladder-style overdrive of classic filters.

CV tap override cable patched into any tap CV jack (ALL, BP6, LP12, BP18, LP24, 2nd H)

Patching disables the corresponding button. CV voltage determines state: <+1V off, +1V to +3V green (non-inverted), >+3V red (inverted). Allows sequenced filter-morph patches by stepping between tap states under CV.

Dual CV inputs for FM patching CV1 and CV2 with knobs past 0

Each of CV1/CV2 has its own attenuator and phase-invert. Scale 0 to 3.6 oct/V. Sockets are DC-coupled for audio-rate FM. Phase invert lets two correlated modulators partially cancel or reinforce. Combined with 1V/Oct and 0.5V/Oct sockets, the filter has five simultaneous frequency CV paths.

Knob-programming caveat rapid real-time twisting of Freq or Reso

Manual explicitly states these are programming controls, not performance potentiometers. Abusing them voids warranty coverage. Real-time sweeps should be done via CV — the module is designed to be sequencer / foot-pedal / external-controller driven.

Clip LED at output output stage signal exceeds headroom

Red clip LED on front panel shows output clipping — use Gain knob to back off, especially at high self-oscillation levels or with Drop pushed. Drive LED on the input side independently lights at 2Vpp to indicate overdrive onset.

Controls

Global Freq Cutoff / centre frequency. Knob range 2Hz to 35kHz; external CV extends to 40kHz at top and essentially no limit at bottom.
2Hz – 35kHz knob · ~40kHz via CV
Global Reso Resonance / Q factor from 0 (no peak) to self-oscillation. Onset depends on Emph setting (~Reso=6 when Emph=1, ~Reso=8 when Emph=0.3).
0 – ∞ · self-osc onset shifts with Emph
Global Emph Level of emphasis / self-oscillation independent from resonance Q. Low values produce a whisper-quiet self-osc that sits in the mix; high values produce large self-osc levels.
0.05 (weak) – 1 (strong) · unique per-filter-level control
Low-pass modes only Drop Compensates the low-frequency gain loss that occurs when resonance is raised on LP filters. Only active in low-pass configurations; yellow on-LED confirms.
-12dB to 0dB · LP only · -3 to -6dB is a good compromise
Global Gain Output gain trim between filter tap and output jack. Red clip LED warns of output stage clipping.
-20dB to 0dB · use to tame self-osc levels
Audio Input1 Attenuator for audio input 1. Paired with a switch selecting 0dB or +20dB boost for the input preamp.
-∞ to 0dB · switch: 0 / +20dB
Audio Input2 Attenuator for audio input 2. Paired with a phase-reverse switch (0° / 180°).
-∞ to 0dB · switch: 0° / 180°
FM CV CV1 / CV2 Two scalable frequency CV inputs with adjustable attenuation and a 0°/180° phase invert switch each. Range per input: 0 to 3.6 oct/V.
0 – 3.6 oct/V per input · phase invert per input
Resonance CV CV-Res Attenuator and phase-invert for the Reso CV input. 0V-5V drives resonance from 0 to self-oscillation.
0 – self-osc/5V · phase invert included
Global 2nd Harm button Adds soft 2nd-harmonic (overtone) distortion post-filter. Enhances warmth, increases at higher resonance. Button inactive when CV is patched into 2nd H jack (LED still shows status).
On / Off · lights red when active · CV overrides button
Slope / tap mixer ALL / BP6 / LP12 / BP18 / LP24 buttons Five filter-tap selectors. Each button cycles off → green (+ added) → red (- subtracted) except ALL which is on/off only (blue). Combinations of the five produce 121 distinct filter shapes.
off / green(+) / red(-) · ALL = blue on/off · CV override per tap

I/O

IN · 12

  • Input1 ±12V AC AUDIO
    AC-coupled audio input 1 with +20dB preamp option.
  • Input2 ±12V AC AUDIO
    AC-coupled audio input 2 with phase reverse.
  • CV1 ±12V CV
    DC CV input for frequency modulation. Scaling set by CV1 knob (0 to 3.6 oct/V).
  • CV2 ±12V CV
    DC CV input for frequency modulation. Scaling set by CV2 knob.
  • 1 V/Oct 1V/oct CV
    Calibrated 1V/octave input for pitch-tracking filter cutoff.
  • 0.5 V/Oct 0.5V/oct CV
    Non-calibrated 0.5V/octave input for slower cutoff tracking.
  • Emph 0-5 V -5V to +5V CV
    CV input added to Emph knob value. Covers entire Emph range.
  • Reso 0-5 V -5V to +5V CV
    CV input for resonance. +5V with Reso=10 = maximum; -5V with Reso=10 drops Reso to 0.
  • Reso (CV) ±12V CV
    DC CV routed through CV-Res attenuator and phase switch.
  • ALL -12V to +12V (AC or DC) GATE
    Gate-style CV override for ALL tap: ≥+3V = on, ≤+2V = off. Button disabled while patched.
  • BP6 / LP12 / BP18 / LP24 -12V to +12V (AC or DC) CV
    Tap-override CV inputs: ≥+3V = inverted, ≥+1V = non-inverted, <+1V = off. Sockets accept full audio range.
  • 2nd H -12V to +12V CV
    CV override for 2nd Harmonic button. ≥+3V on, ≤+2V off, hysteresis between.

OUT · 1

  • Output Clip LED at output stage limit AUDIO
    DC-coupled filtered audio output. Offset trimmable via rear P7 trimmer.