Percussive Enveloping Noise Generator
Features:
-555 driven envelope
-Triggerable by almost anything, at any length+
-Attack cannot be retriggered until decay starts (this can make for some interesting half time hits if trigger is faster than attack time)
-Transistor Noise generator
-Beginner style DIY build
-It's mostly analog!
Notes on building: If you want a longer attack and decay, swap the capacitor on C5 from 4.7uF to 10uF (16V or larger)! Experiment! Have Fun!