An envelope generator in 2HP. Attack, decay, a trigger input and an output — the essentials, in the narrowest space a Eurorack module can occupy.

Both stages have their own CV input with an attenuator, which is more than most compact envelopes offer. That means attack and decay times can themselves be modulated: an LFO on the decay makes repeated hits breathe, a random source on the attack makes every note articulate slightly differently.

The switch selects between linear and exponential response, and it matters more than it sounds. Exponential curves follow how we perceive loudness, so they're the natural choice for amplitude and for percussive shapes with a snappy attack. Linear curves track the voltage directly, which is what you want when the envelope is driving pitch, filter cutoff or anything where predictable scaling beats musical feel. Having both in one module means it can cover either job as the patch changes.

Racks tend to run short of envelopes long before they run out of anything else, and this is the cheapest way in terms of space to add one more.

Condition: excellent. Panel clean with no rack rash, both knobs and the jacks tight, mode switch working. Tested and working. Ships with ribbon cable and mounting screws.

Specs: 2HP Eurorack.

Shipping from the Netherlands, tracked. Offers welcome.