Envelope generators are used to control several important sound parameters in analog synthesizers, such as pitch, volume, filter frequency etc. In a conventional synthesizer, envelopes govern how these parameters should respond over time - from the moment a note is struck to the moment it is released. In the Dr.Rex device however, the envelopes are triggered each time a slice is played back.
There are two envelope generators in the Dr.Rex, one for volume, and one for the filter frequency (and/or pitch). Both have the standard four parameters; Attack, Decay, Sustain and Release
Please refer to the Subtractor chapter for a description of the basic envelope parameters.
The Amp Envelope governs how the volume of a slice should change over time, from the time it is triggered (the slice note starts) until the slice note ends. This can be used to make a loop more distinct (by having a snappy attack and a short decay time) or more spaced-out (by raising the attack time).
The Level parameter acts as a general volume control for the loop.
The Filter Envelope can be used to control two parameters; filter frequency and overall loop pitch. By setting up a filter envelope you control how the filter frequency and/or the pitch should change over time for each slice.
The Amount parameter determines to what degree the filter frequency will be affected by the Filter Envelope. The higher the Amount setting, the more pronounced the effect of the envelope on the filter.
Try lowering the Frequency slider and raising Resonance and Envelope Amount to get the most effect of the filter envelope!