Noise Engineering - Sinclastic Empulatrix

Sinclastic Empulatrix combines a very percussive Attack-Decay envelope generator with a VCA in just four HP width. The envelope output is normalized to the VCA and for that reason the module is just perfect when you want to create your own drum voices - just connect an audio source and a gate - ready! On the other hand it's very handy when you fly a lot to gigs and need a compact system.

The Sinclastic Empulatrix envelope has an exponential curve and the time range of the attack and decay phases goes from 50us to 5s (or 3.5 times as long with a different jumper setting). The Gate/Trig switch select if the envelope reacts to the entire gate or just the rising slope which is great for superfast percussive envelopes at minimal attack setting. The HIT button, used for manual fireing of the envelope always generates a gate, no matter which setting the Gate/Trig switch is at.
The output level of the envelope is depending on the gate level and approximately 2x as high as the gate: when the gate is +5V the envelope output will be around 0-10V

The VCA has no CV input but is modulated directly by the envleope. The circuit is not a classic VCA but a so-called "clamp" which clips the signal instead of scaling it. As the envelope decays it will start chopping off the top (and bottom) of the audio waveform.

The module is inspired by the combination of envelope generator and VCA as used in the 808's hi hat section. This circuitry hasn't been exactly cloned; the envelope times have been shortend and some different components have been used.