Rate
LFO speed in Chorus/Flange modes (ignored in some other modes).
- Turn up Faster modulation.
- Turn down Slower swirl.
Pedals / Multi-mode modulator
Poly Chorus
Multi-mode modulator · play-tested
seth — fish
seth@ninevolt:~$
Knobs
In the TUI each knob runs from low (left / 0%) to high (right / 100%). Start near noon, then nudge while you play.
Width
How far the modulation sweeps.
- Turn up Wider, more dramatic movement.
- Turn down Narrower, subtler movement.
Tune
Base delay time / center of the effect.
- Turn up Longer delay center — bigger, slapper textures in some modes.
- Turn down Shorter delay — tighter flange/chorus territory.
Feedback
How much effected signal feeds back into itself.
- Turn up More resonant, metallic, repeating character.
- Turn down Cleaner single-pass modulation.
Mode
Chooses the effect personality (sweep this continuously to hear regions change).
- Turn up Moves through Chorus → Flange → Filter Matrix → Double Track regions.
- Turn down Stays toward classic chorus-style behavior at the low end.
Blend
Dry guitar versus effected sound.
- Turn up More effect in the mix.
- Turn down More dry guitar; effect sits underneath.
Sweep Filter
Extra high-band emphasis on the wet sound.
- Turn up Brighter, more filtered sweep character.
- Turn down Less filter emphasis — smoother wet path.
Inspired by
Electro-Harmonix Stereo Polychorus / vintage PolyChorus · PolyFlange · EchoFlanger family — MN3007 BBD chorus/flange. Kurt Cobain In Utero mod texture (EHX Stereo Polychorus manual (PDF)).
Not tremolo — LFO modulates delay read time (Chorus/Flange modes), not gain (Molo Trem). Time/mod family: TIME_MOD_COMPARISON.md.
Signal path
| Step | What it does |
|---|---|
| Input + feedback | Last wet × mode-scaled Feedback into sum before LP. |
| Input LP 5.5 kHz | BBD bandwidth conditioning. |
| Delay line write | Up to ~240 ms ring buffer. |
| Modulated read | Chorus: 8–48 ms + Width sweep. Flange: 0.5–8 ms tight sweep. Filter Matrix: static Tune. Double Track: Tune → slapback ms, no LFO. |
| Sweep Filter | Optional HF emphasis on wet (120 Hz–2.3 kHz blend). |
| Mode blend | Chorus wet + flange comb term — laws differ per Mode (see code). |
| Blend | Clean input vs effect bus. |
| Output | Clamped ±1. |
Simplifications
- Mono — no stereo anti-phase outputs - Digital delay — no BBD clock resampling / companding - Double Track is short slapback here; long echo + flange is Echo Flange