The envelope modifies the loudness contour of a sound. It takes a sound input and shapes it into something you’d hear from an acoustic musical instrument, like a piano or saxophone.

The envelope of a sound has a big effect on the character of the sound. The envelope Bit is a modulator, which is an element of a synthesizer that alters the main audio signal with another signal.

The envelope Bit has two controls: ATTACK, which is how long it takes to ramp up to maximum volume, and DECAY, which is how long it takes to fade to silence again. You can use its third bitSnap to trigger the envelope from different sources, like the keyboard.

To emulate a bowed instrument, use a longer attack and decay time. To emulate a string pluck, use no attack and a short decay time. To emulate a percussive stirke, use no attack and vary your decay time to short or medium times.