This is a very common problem with Wurlitzers and could be due to many things. Here is a list of the most likely culprits:
⁃ The hum shield (the case that covers the hammers and is designed to prevent buzzing) is not set properly. Readjusting this can fix the problem.
⁃ Loose screws – a screw (or more) is loose inside the wurlitzer and the vibration of the sound is causing it to rattle.
⁃ Dust/debris in the speakers – The speakers of a wurlitzer are often overlooked during serivixnf. Often dust or debris is inside here and can cause buzzing problems.
⁃ Broken speaker – when the cone of a speaker is damaged it can create a distorted sound or buzzing. The speaker will need to be replaced.
⁃ The wurlitzer case doesn’t fit properly. One of the more irritating buzzing issues can come from the top half of the wurlitzer case not sitting flush with the bottom half. This can happen due to years of expansion and contraction of the wood that makes up the body of the piano. The wooden rim will need to be sanded down to fit the rim if it’s too tight or shims added if it’s too loose.
⁃ Damaged electronics – sometimes a damaged wire, capacitor, transistor can cause buzzing. This is more difficult to diagnose as the circuit board needs to be tested.
