[sdiy] Vactrols and contact mics

[aghostAGHOSTaghost]

I'm curious if anyone has experience with driving the LED of a vactrol
with a contact mic.  The contact mic would be attached to a drum so
I'm guessing the voltage would be high enough to light the LED but
would it be very instantaneous or perhaps it needs to be amplified?
Would it be simple to create some sort of decay?  Ultimately I would
like to be able to trigger a voltage controlled dimmer connected to an
incandescent bulb with a drum.
Thanks
Walter