Quick Reference
Cascadia Signal Flow
With no cables patched, the Cascadia produces sound through these normalled connections:
Diagram key: Solid arrows (-->) show the primary audio signal path from oscillator to output. Dashed arrows (-.->) show modulation normalling and secondary connections that shape the sound but are not part of the main audio chain.
What Each Connection Does
Primary Audio Path (solid lines)
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MIDI/CV -> VCO A pitch: MIDI note data sets the pitch of VCO A via 1V/octave CV. This is the main pitch source for the instrument.
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MIDI/CV -> VCO B pitch: MIDI pitch is also normalled to VCO B (when its PITCH SOURCE switch is set to PITCH A+B), keeping both oscillators in tune.
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VCO A -> Mixer: VCO A's waveform outputs (saw, pulse, triangle) feed the Mixer, where they are blended with noise, sub-oscillator, and external inputs.
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Mixer -> VCF: The mixed signal enters the voltage-controlled filter for spectral shaping. Patching into VCF IN overrides this connection.
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VCF -> Wave Folder: The filtered signal passes through the wave folder. Even with folding at minimum, the signal passes through to VCA A.
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Wave Folder -> VCA A: The wave folder output is normalled to VCA A's input, completing the audio chain before the output stage.
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VCA A -> Output Control: VCA A's output is normalled to the MAIN 1 input on Output Control, which drives the headphone and line outputs.
Modulation Normalling (dashed lines)
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Envelope A -> VCA A (CV): Envelope A's output controls VCA A's amplitude. This is the amplitude envelope -- it shapes every note's volume over time (attack, decay, sustain, release). Patching into VCA A's LEVEL MOD IN overrides this.
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Envelope A -> VCO A (IM): Envelope A is normalled to VCO A's Index Modulation input, allowing the envelope to control FM depth. The IM MOD slider sets how much this affects FM 2 intensity.
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Envelope B -> VCF (FM 1): Envelope B modulates the filter cutoff frequency via FM 1. This creates the classic "envelope-controlled filter sweep" heard in plucky and percussive sounds. Patching into VCF FM 1 IN overrides this.
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MIDI/CV -> VCF (FM 2): MIDI pitch is normalled to VCF FM 2, providing keyboard tracking for the filter. This keeps the filter cutoff proportional to the note being played, essential when the filter is self-oscillating.
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MIDI/CV -> Envelope A (velocity): MIDI velocity is normalled to Envelope A's CTRL input. Depending on the CTRL SOURCE switch, this scales either the envelope's amplitude or its overall time -- softer notes play quieter or slower.
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MIDI/CV -> Envelope A (gate): MIDI gate triggers Envelope A. The gate going high starts the attack stage; the gate going low triggers the release stage.
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MIDI/CV -> Envelope B (gate): MIDI gate also triggers Envelope B, so both envelopes respond to the same note events by default.
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VCO B -> VCO A (FM 2): VCO B's sine wave output is normalled to VCO A's FM 2 input. This enables frequency modulation synthesis with zero cables -- use VCO A's INDEX slider to dial in FM depth.
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LFO X/Y -> VCO A (PWM): LFO Y is normalled to VCO A's pulse width modulation input. Raising the PW MOD slider adds movement to the pulse wave output. LFO Z is normalled to MULT IN 1 in the Patchbay for distribution.
This session builds on Session #25 — complete it first for the best experience
Session 26: Partial Recipe -- Metallic Texture
Session 26: Partial Recipe -- Metallic Texture
Objective: Build a shimmering, metallic texture using wave folding, FM, and modulation. This session gives you the target sound and most of the steps -- but leaves key decisions to you. Each blank draws on a specific skill you developed earlier in the curriculum.
Remove all cables. VCO A OCTAVE 5, Mixer SAW ~40%. Wave Folder FOLD ~45%. VCF FREQ ~55%, MODE BP. Hold a note -- instant metallic shimmer.
Target Sound
A bright, harmonically complex texture that glitters and shifts. Think struck metal slowly vibrating in a reverberant space -- the wave folder generates dense overtones while modulation creates evolving spectral movement. The sound should be static enough to feel like a texture rather than a melody, but alive enough that sustained listening reveals constant subtle change.
Starting Patch
Remove all cables. Set all knobs and sliders to noon/center. This is the Cascadia equivalent of loading the basic patch -- a known, neutral starting state.
Steps
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Set VCO A OCTAVE =
5and PITCH = noon -
Set Mixer: SAW = ~40%, all other sliders = 0%
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Set Wave Folder FOLD =
____(hint: Session 03 covered wave folding and FM -- how much folding adds dense metallic harmonics without turning into noise? Think about where the sweet spot sits between subtle warmth and aggressive crunch.) -
Set VCF MODE =
____(hint: Session 10 explored filter modes -- which mode lets the wave-folded harmonics through while still shaping the tone? Consider what each mode removes and what it preserves.) -
Set VCF FREQ = ~55%, Q = ~20%
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Set Envelope B: Attack = ~10%, Decay = ~50%, Sustain = ~30%, Release = ~45%
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Set VCF FM 1 = ~30% (envelope shapes the filter sweep on each note)
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Set Envelope A: Attack = ~5%, Decay = ~35%, Sustain = ~60%, Release = ~40%, ENVELOPE SPEED = Fast
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Patch LFO X OUT -> VCF FM 3 IN. Set FM 3 = ~20%, LFO RATE =
____(hint: Session 14 covered LFO basics -- what rate creates evolving metallic shimmer rather than obvious wobble? Think about the difference between rhythmic modulation and textural drift.) -
Set VCO A INDEX = ~15% for subtle FM shimmer from the normalled VCO B
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Set SOFT CLIP = On for warmth on the output
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Hold a note in the C4-C6 range. The sound should glitter and shift -- dense harmonics from the wave folder, shaped by the filter, with slow LFO movement adding life.
Listen For
- Dense, metallic overtones from the wave folder that shimmer rather than screech
- A filter character that shapes the texture without removing the harmonics that define it
- Slow spectral movement from the LFO modulating the filter -- perceptible but not distracting
- Subtle FM richness from the VCO A INDEX adding complexity to the oscillator tone
Reflection
What values did you choose for the three blanks? The wave folder amount determines whether the texture is warm-metallic or harsh-digital. The filter mode determines which harmonics survive. The LFO rate determines whether the sound feels static or alive. Compare your choices to Session 24's texture patch -- how does your approach differ? Write down your values and reasoning.
Output Checklist
- Metallic texture patch completed with all blanks filled in
- Cable routing documented (LFO X -> VCF FM 3)
- Parameter values documented with reasoning
- Patch documented in patches/cascadia/ with full knob settings and cable routing
- Session logged in Obsidian daily note