swell is an unusual kind of smoothing filter from sndkitthat dynamically changes it's weight based on which direction the control signal is going in.

Here's a hasty test patch using it. This will create a knobs with the first Arc knob controlling the frequency of a lowpassed sawtooth oscillator . Moving the frequency upwards will produce little resistance. Moving the frequency downwards will trigger the heavier smoothing time, causing the sensation that things are "powering down".

Initialization and setup:

(monolith:knobs-new "k")
(monolith:page-select "k")
(monolith:knobs-select "k" 0 0 0)
(monolith:load "knobs.scm")
(monolith:load "ugens.scm")

The actual patch, after setup:

(knobsval 0 0 0 "k")
(swell zz 0.001 3 0.1)
(scale zz 150 300)
(blsaw zz 0.5)
(butlp zz 800)
(out zz)