Ladder filter

ATMOSYNTH built-in module

A low-pass that sings. Four poles with a feedback around them, and Resonance is how much: below one it emphasises what is at the cutoff, at one the feedback exactly makes up for what the poles take off, and above one the filter holds a tone of its own with nothing played into it at all — the whistle the Moogs and the Junos are asked for, and the one thing the ordinary Filter cannot do however far its resonance is pushed. Cutoff and Cutoff amount work as they do there, in cents and negative to invert; Key tracking moves the cutoff with the note played, which needs the note routed here. Drive is how hard the sound is pushed into the filter's own saturation, at one gently and above it into the thick, compressed sound that saturation is wanted for; it is kept out of the feedback, so driving the filter does not move the point at which it starts to sing. This module carries code: nothing in the vocabulary can be fed back into itself a sample at a time, which is the whole of what a filter like this is.

What this module is made of is not shown here. Fork it into the editor to see for yourself.