For some, the ARP 2500 might be the holy grail of synthesizer history. Definitely rare, extremely impressive in its dimensions, sonically overwhelming and then as now a unique specimen. Built from 1970 to 1981, this dinosaur of analog synthesizers looks very tidy despite its modularity implemented throughout, thanks to the router system used. Behringer has reduced the modules to the compact Eurorack format and meticulously kept to the historical originals both functionally and sonically.

The Behringer Dual Envelope Generator 1033 is a dual ADSR envelope that can be measured against the percussive time and curve of the original. The "Final Decay" parameter is what is declared as the release phase in other envelope modules. The two envelopes are triggered with a common gate socket; a restart is provided via the trigger input. In addition, each unit has an integrated gate delay that makes it possible to delay the release time of the attack phase. For each unit, a toggle switch can be used to select whether the retrigger is active or not. Thanks to the manual gate buttons, the envelopes can also be triggered without a keyboard or sequencer.