So I've used this setup before on just a plain piezo on the table:
It worked great for just controlling a solenoid (what I was using it for).
I'm now building some drum triggers into my acoustic drums to drive an Arduino which will send MIDI data.
I've seen most drum triggers use a foam cone similar to this:
I plan on incorporating some threshold control into the circuit (with a pot), but I want the triggers to be as sensitive as possible. The circuit above seems to clean/condition the signal a bunch, but that's just a raw piezo being used (as are most other arduino triggers I've seen on here).
I guess it's more about if anyone has used one of those foam cones in a trigger circuit.
I've had good luck using these pressure sensors as drum triggers. They are available from Sparkfun.
I read the pressure, determine the maximum pressure of the hit, send that to Max4Live, convert the pressure into a midi velocity and generate a midi note. All that midi nonsense could be done right on the arduino as well.
Aren't those kind of pricey? Not to mention size wise, on an acoustic drum head, it would have a serious muffling effect.