Somehow managing to haul myself to thejamjar early on Saturday morning after a serious DnB night, and after a quick encaffeination, I joined the other participants as we set to work putting together one of these:
It's a contact microphone. Basically, it's a standard piezo transducer component that rests on a bed of solid silicone glue in a bottle cap and is wired to an audio socket. A protective putty layer allows it to stick onto and pick up vibrations from solid objects, such as these:
It looks like a lot of random-looking kitchen utensils and appliances, but these were organized as per their ability to generate a sound that can be integrated into our orchestra.
Like Jedi padawans must create their own lightsabers to become knights, we had to construct our own contact microphones, using the above tools.
After stripping the ends off the audio cables and cutting them to size, we coat the exposed leads with lead solder.
Then we solder one end to a dismantled audio socket, which will be jacked into an amplifier and speaker.
The other end is soldered onto the leads of a piezo transducer disc.
After the soldering is done, the socket is reassembled.
Then, the cap is filled with silicone glue, and the transducer is pressed onto the glue just as it is about to seal dry.
The Fun-Tak putty is then used to seal the transducer on the glue. We had a great time using our mics to rehearse with the utensils and appliances, and I look forward to the performance at month-end.