It's basically a pickup which gives acoustic style sounds. They're installed on the bridge of the guitar. I think you need a pre-amp for them to work though.
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Quote by utsapp89
^I'd let a pro look at it. Once you get into the technicalities of screws...well, it's just a place you don't want to be, friend.
Instead of creating a signal by having an object vibrate through a magnetic field, like a standard magnetic pickup does, a piezo pickup creates an electrical impulse when it itself is vibrated. That's why you see them installed under the saddles of acoustic guitars or in the bridges of electric guitars.
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