Threshold
How quiet the guitar must get before the gate mutes hiss and hum.
- Turn up Gate stays open more — only very quiet noise is cut (less chopping).
- Turn down Gate closes sooner — tighter silence between notes, but can choke sustain if too low.
Pedals / VCA noise suppressor
Hush Gate
VCA noise suppressor · 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.
Decay
How quickly the gate closes once it decides to mute.
- Turn up Slower close — more natural ringing out.
- Turn down Faster close — abrupt silence, great for staccato riffs.
Inspired by
Boss NS-2 Noise Suppressor (1987) — high-speed VCA + envelope detector downward expander with Send/Return loop for isolating noisy gain pedals. Threshold sets where suppression begins; Decay sets how long the gate holds open after the signal drops (MIN = tight chop, MAX = natural tails). Profiles use it after high-gain distortion (Misfits, Manson, Metallica-style chains). Software runs Reduction behavior inline — no Send/Return loop or Mute mode switch.
Signal path
| Step | What it does |
|---|---|
| Input HPF ~85 Hz | Keeps sub rumble out of the detector. |
| Peak envelope attack/release | ~1.8 ms attack; release 22–780 ms from Decay (MIN tight, MAX natural). |
| Downward expander VCA | Below Threshold, gain follows smooth power curve; above = unity. |
| Input × gain | VCA multiply on conditioned input. |
| Clamp ±1 | Output limit. |
How we modeled it
NS-2 Reduction path: input HPF → peak envelope → VCA expander → multiply. High Threshold cuts hiss between notes without needing a hard mute. Low Decay tightens rhythm-metal chug; high Decay lets sustained notes breathe.
Simplifications
- No Send/Return loop (inline gate only — profiles place it after distortion) - Mute mode and footswitch CHECK behavior not modeled - Single-channel, not dual-band - Detector on input path, not separate loop-return tap