Something rattles, vibrates, hums

• Please insert a completely fresh set of new batteries or full batteries first, because even a poor power supply can be noticed by a croaking sound.
• Then we should exclude that it is only a loose screw, or that only the rear wall vibrates, because it should be tightened, for example. Therefore, please remove the sliding cover first. Then listen to the device at full volume with the rear panel open, whether it is still vibrating.

Is the problem still there?

• If yes, please try by laying it on the speaker grille by hand, whether it lies only on the speaker grille or the wooden frame on the speaker grille (and one of the 4 screws may be too loose there).

If you have a loose screw, you can tighten it yourself with feeling. This problem can be caused by differences in humidity and temperature when the wood”works” (expands or contracts slightly). Is the problem still there?