SW3 Splice

DPW Design 6HP
SWITCH UTILITY LOGIC

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Fully analog 2-channel click-free signal splicer/switcher. Each channel picks between A and B via three switching modes (equal-level, equal-slope, hard) with manual or CV/gate control, at switching rates up to 200 kHz.

Patch Ideas · 4

Click-free crossfade between two oscillators
Replace a crossfader: hard-pick between two VCOs with zero pop, using equal-slope mode so the transition is inaudible.
Walkthrough
  1. Patch VCO 1 → SW3 A1.
  2. Patch VCO 2 → SW3 B1.
  3. Set channel 1 mode switch to '=' (equal level + equal slope).
  4. Set channel 1 division to '1'.
  5. Set channel 1 input select to 'A' (start on VCO 1).
  6. Patch SW3 OUT1 → VCA IN → mixer.
  7. Flip the A/B switch manually, or patch a slow gate to D input and set input select to 'Auto' to let the module wait for a clean crossing.
Signal out OUT1 — the selected VCO at full level, mono, no click.
Listen for A completely seamless swap between the two oscillators — you'll hear the new pitch but no pop or glitch at the transition, even mid-note.
▸ Show diagram
Patch diagramPatch diagram with 7 modules and 5 connections. Signals: 4 audio, 1 cv.SW3 SpliceVCO 1SW3VCO 2Gate SourceVCAMixerCH1 mode: =CH1 div: 1CH1 sel: AutoOutaudioA1audioB1audioDcvOUT1audioOutaudioOutcvInaudioOutaudioInaudioaudiocv
Sub-octave from a single VCO
Use Auto mode with /2 or /4 division to splice a VCO with itself inverted, producing clean sub-harmonic octaves.
Walkthrough
  1. Patch VCO saw out → SW3 A1.
  2. Patch the same VCO through an inverter (or the inverted out of a mult/attenuverter) → SW3 B1.
  3. Set channel 1 input select to 'Auto' (center).
  4. Set channel 1 mode to 'X' (equal-level).
  5. Set channel 1 division to '/2' for one octave down, or '/4' for two octaves down.
  6. Patch SW3 OUT1 → mixer channel.
Signal out OUT1 — sub-octave of the input VCO, same waveform character.
Listen for A clean sub-octave that tracks the VCO 1:1. /2 gives one octave down, /4 gives two. Switching back to /1 returns the original pitch — great for bass thickening under a lead.
Stereo ping-pong with one gate
Use the swap stereo mode to bounce a mono source between L and R at gate speed, synced to your clock.
Walkthrough
  1. Patch mono source → SW3 A1 and → SW3 B2 (so A1=source, B2=source).
  2. Patch silence (or a second source) → SW3 B1 and → SW3 A2.
  3. Set the stereo switch to 'swap'.
  4. Set both channels' mode to 'H' (hard switch) — we want sharp rhythmic moves.
  5. Patch a clock or rhythmic gate → D input.
  6. Patch SW3 OUT1 → stereo mixer L, SW3 OUT2 → stereo mixer R.
Signal out OUT1 / OUT2 — hard-panned ping-pong of the source, following the gate.
Listen for Each gate pulse jumps the source from left to right speaker and back. Tempo-sync the gate for rhythmic panning; use a fast LFO for a tremolo-pan.
▸ Show diagram
Patch diagramPatch diagram with 5 modules and 5 connections. Modules: SW3 Splice, Source, SW3, Clock, Mixer. Signals: 4 audio, 1 cv.SW3 SpliceSourceSW3ClockMixerStereo: swapCH1 & CH2 mode: HOutaudioA1audioB2audioDcvOUT1audioOUT2audioOutcvLaudioRaudioaudiocv
Gate from an audio-rate splice (ON output trick)
Turn the ON logic output into a rhythmic gate source derived from the music itself — no sequencer needed.
Walkthrough
  1. Patch a melodic source → SW3 A1.
  2. Patch silence (unpatched) or a second drone → SW3 B1.
  3. Set channel 1 mode to 'X', division to '/4', input select to 'Auto'.
  4. Patch SW3 ON1 → envelope generator Trigger in.
  5. Patch envelope → VCA CV controlling anything (a hi-hat, a reverb send).
Signal out ON1 — +5V gate pulses every 4th zero-crossing of the source.
Listen for Rhythmic gates that lock to the melodic content feeding A1 — faster notes produce faster gates. A free 'groove follower' for triggering percussion or accents off a bassline.

Behaviors

Click-free equal-level splice (X mode) mode switch in X, Auto selected

Flip from A to B only happens at instants where A and B are at the same voltage. Prevents the discontinuity that causes clicks when cross-fading full-range signals.

Slope-matched splice (= mode) mode switch in =

Flip only when A and B are equal AND moving in the same direction. Cleanest possible splice on audio — you rarely hear the transition at all.

Hard switch (H mode) mode switch in H, D input driven

Immediate A/B swap on the rising edge of D. No click avoidance. Use for rhythmic wave-chopping and percussive bursts.

Division / sub-harmonic division switch on /2 or /4, audio through A and B

In Auto mode, only every 2nd or 4th crossing triggers a flip, producing a sub-octave alternation on periodic signals — a sub-harmonic generator.

Stereo link stereo switch set to link

Both channels follow channel 1's control decision simultaneously — a stereo signal (L → A1/A2, R → B1/B2) switches as a pair.

Channel-swap stereo stereo switch set to swap

Channel 2 mirrors channel 1 with A/B swapped. Patch left to A1/B2 and right to B1/A2 for hard stereo ping-pong on the same gate.

ON logic output whenever input A is selected

ON1/ON2 emit a +5V gate while A is active — use them as trigger sources, clock dividers, or to drive envelopes in sync with the splice.

Controls

per channel (1 and 2) A / Auto / B (Input select) Forces input A, input B, or Auto where the module toggles when A and B momentarily match.
3-position toggle. In Auto, the switch flips at every moment A and B cross, so a mono signal self-splices instead of being manually chosen. Up = A, down = B, center = Auto.
per channel 1 / /2 / /4 (Toggle division) Divides how often the auto-toggle actually flips — every crossing, every other, or every fourth.
Acts as a sub-harmonic generator when the signal is an oscillator: /2 and /4 introduce octaves/sub-octaves into the composite output. Works in Auto mode and with the D (gate) input.
per channel X / = / H (Splice mode) Chooses the click-free rule: X = match when equal, = = match when equal and slopes align, H = hard switch.
X waits for level equality before flipping (click-free on most signals). = is stricter and waits for equal level AND same slope direction (cleanest on audio). H ignores matching and hard-switches immediately — use for percussive effects or when driven by gates.
global (2 switches near channels) Stereo mode switches Link channel 2 to channel 1 (stereo), swap the two outputs, or keep them as two independent mono switches.
Lets you use the module as: dual mono (two separate switches), stereo-linked (one decision drives both OUTs so a stereo pair switches together), or swap (channel 2 inverts the A/B choice, useful for stereo panning/ping-pong).

I/O

IN · 6

  • A1 audio or CV, ~100 kΩ input impedance CV
    Channel 1 source A.
  • B1 audio or CV, ~100 kΩ input impedance CV
    Channel 1 source B.
  • A2 audio or CV, ~100 kΩ input impedance CV
    Channel 2 source A.
  • B2 audio or CV, ~100 kΩ input impedance CV
    Channel 2 source B.
  • D (Drive) gate / CV, up to 200 kHz switching GATE
    External control input for switching logic. With mode switch on H, this gate/CV chooses A or B directly; in X/= modes it can force reconsideration.
  • R (Reset) gate / trigger GATE
    Reset input — resets the auto-toggle flip-flop and division counter to a known state.

OUT · 4

  • OUT1 audio or CV, 3.3 kΩ / 20 Ω through-switch impedance CV
    Channel 1 spliced/switched output. Carries whichever of A1/B1 is currently selected.
  • OUT2 audio or CV, 3.3 kΩ / 20 Ω through-switch impedance CV
    Channel 2 spliced/switched output. Independent, linked-to-1, or swapped depending on stereo switches.
  • ON1 0 / +5V gate GATE
    Logic output for channel 1. Goes to ~5V whenever input A1 is the one currently selected.
  • ON2 0 / +5V gate GATE
    Logic output for channel 2. Goes to ~5V whenever input A2 is the one currently selected.