I have been very interested in the apprehension engine lately and as a proof of concept I thought I’d throw a little prototype together from things I had lying around the house.
It turns out that things that look resonant are not always resonant (the large spines sticking out were coated with some plastic) and it’s not easy to make a miniture hrdy gurdy. However, I still think there are some interesting outcomes from this experiment.
Someday I will get around to building a full scale version with a hurdy gurdy on board.
The whole thing is amplified by a piezo within the box, which runs into a little TL071 preamp.