Saturator

Smooth, musical tanh saturation — the gentle "always-on" warmth that rounds transients and thickens a signal without hard edges. This is the standalone form of the Distort module's Classic mode, pulled out on its own and given two extra controls.

How it works

The signal is driven into a tanh curve: out = tanh((Drive·49 + 1) · in · 0.5). Because it always shapes (there's no clean-at-zero bypass), even a little Drive adds a touch of softness. Classic is intentionally gentle — the output peaks around ±1 V no matter how hard you push — so reach for Level when you want a hotter signal.

Controls

  • Drive — 0–1. How hard the signal hits the curve. Low values barely

round the peaks; high values fold transients into a soft, compressed wall.

  • Bias — 0–1. Adds tube-like even harmonics by shifting the signal

off-center before shaping (DC-compensated, so it stays centered at the output). At 0 the curve is perfectly symmetric and the module is identical to Distort's Classic. Turn it up for a warmer, more "tubey" grit.

  • Level — 0–2. Makeup gain on the output. Since Classic peaks low,

raise this to bring the saturated signal back up (or past) unity.

Inputs & outputs

  • In L / In R — audio to saturate. Mono? Just use L — it's processed once

and sent to both outputs. Patch a stereo pair and each side gets its own saturation path through the shared knobs, so a wide source stays wide.

  • Drive / Bias CV — modulate Drive and Bias. Each takes ±10 V and folds

to ±half the knob's range around the knob setting, then clamps. Unpatched, they do nothing — the knobs rule.

  • Out L / Out R — the saturated signal. With stereo in but only L cabled,

the channels fold to mono automatically so nothing goes missing.

Tips

  • Keep Drive low and patch an envelope or LFO into Drive CV for

dynamic, playing-responsive warmth.

  • A little Bias (0.1–0.3) on bass or pads adds body; too much starts to

sound lopsided — that's the even-harmonic asymmetry talking.

  • For a true overdrive lift, push Drive and pull Level up to taste;

for transparent glue, barely touch Drive and leave Level at 1.