one_pole_smoother

NODE

Slows down the control signal travelling on the aux bus. It never touches the main signal.

Parameters

FIELD	WHAT IT DECIDES	RANGE	REQUIRED
time_ms	Time constant [ms].	0.01 〜 5,000	yes

{
  "time_ms": 20,
  "type": "one_pole_smoother"
}

How it is computed

a first-order low pass with a time constant of time_ms, applied to the aux bus only

the main signal is passed through unchanged

It is the same arithmetic as the DC blocker, run on a different bus. The difference between the two nodes is what they are connected to, not what they compute.

Using it

This is where the recovery time of a sag comes from.
signal_gain has no time constant of its own. How slowly the level comes back after a loud passage is decided here.
It is not available on the main signal.
A first-order low pass on audio is already writable as a biquad. Offering it twice would mean two ways to do one thing, and two paths into the loudness matching.
It counts as 0 dB in a comparison.
It does not touch the main signal, so it contributes nothing to the level the A/B matching combines.