our contact microphones work by placing the piezo transducer on an object and plugging it in to your amp/mixer/pa. the microphone will pick up any vibrations in the object to which it is attached. you can use it to amplify acoustic instruments. it is also good for studio or field recordings because there is no cross-bleed from other sound sources.
probably the most interesting aspect of contact microphones is their ability to turn anything into an instrument. attach it to any ordinary (or extraordinary) object and record/amplify the vibrations. one sound artist has used contact microphones to record bicycle spokes, branches of a rose bush, spider webs, cactus needles in the wind, etc. the possibilities are endless.
this contact microphone is made with a brass disc piezo element and is attached to approximately 6 inches of shielded instrument cable that blocks interference. it is terminated by a 1/4″ mono female phone jack so that you can connect an instrument or microphone cable of your choice. this allows you to determine the length of cable. the piezo transducer is about 1 inch in diameter. the ceramic side of the disc has been coated in epoxy to make it more durable. some of the mics have been coated in glitter on the ceramic side to make them look better (we think so, anyway), others have just plain old epoxy on them.