ADSR Envelope

A 4 stage linear envelope generator.

Pins

io	letter	name	unit	description
in	T	time	seconds	envelope time
	t	trigger	logic	start, restart and release
out	=		auto	envelope

Controls

name	description
base line	vertical scale
attack decay	initial rise and first falloff
sustain	level at which to hold
release	initial and final release rate

Parameters

name	option	key	description
start	pos	p	start/restart on pos edge, release on neg edge
	neg	n	start/restart on neg edge, release on pos edge
no sustain		s	don't wait for release trigger
no retrigger		r	only start when idle
ignore T		i	only read T at start trigger
auto retrigger		a	restart automatically
small		enter	show object as an icon

Notes

The vertical height is always 1. The Envelope always starts at 0. Adjust the base line control to adjust. Ex: Setting the base line in the middle of the display sets the top at +0.5 and the bottom at -0.5. Controls in between the top and bottom are scaled accordingly. In ABox ver 2.32 the ADSR algorithm was adjusted for more accurate timing. Specifically, output between segments (the corners of the envelope) is now interpolated. This means that at the segment transition, the output will rarely equal the actual value specified by the control circle. As there was no interpolation in previous versions, the ADSR time span was slightly different than that specified at the T input. Changing the timing caused some previous circuits to operate incorrectly. For the sake of backwards compatability, all old versions of the ADSR are preserved and use the previous algorithm. These can be recognized by the 'old' label at the top left of the object. Copy and paste preserves the 'old' status. Newly created ADSRs always use the new algorithm.