how a piezo pickup works in a solid guitar:
Placement: The piezo pickup is often integrated into the guitar's bridge or saddle. In acoustic guitars, it is placed underneath the saddle, while in some solid-body electric guitars, it can be embedded in the bridge or mounted in other locations.
String Vibrations: When you play the guitar, the strings vibrate, creating pressure and mechanical vibrations on the bridge or saddle.
Piezoelectric Effect: The piezoelectric element, which is sensitive to mechanical pressure, converts these vibrations into electrical signals.
Signal Output: The generated electrical signals are then sent to a preamp or onboard electronics in the guitar. The preamp helps amplify and shape the signal before it is sent to an amplifier or a sound system.