Clapper doesn't use any kind of adsr, it uses wave files as a gain envelope for the different frequency range. This makes the envelopes way more complex and it comes with many of those to tweak.
The selectable noise sources are band passed to match different notes. So your clap can sound in key!
You know the Has effect? That very short delay on a side that allow for great stereo but poor mono compatibility? We implemented it not on the sound itself but on the gain envelopes! This way you can have a wider clap than ever, but you keep total mono compatibility because the phase is preserved as only the gain control is delayed not the actual signal passing thru.