If the string of the upright piano is not fully muted after the hammer strikes it.

[maxim_tuner]

https://youtube.com/shorts/W61MShH7AbU? ... S5-pXQnMct
Adjusting the Damper for Better Upright Piano Sound.
In the video, we hears that 'the damper felt head' is not aligned correctly with the string it is supposed to dampen or
'the damper felt' is bad condition there.


If your piano's damper is not effectively muting the strings, follow these steps to fix it:


1 Check 'the Damper Felt': Examine 'the damper felt' to ensure it's in good condition. Gently press or adjust it with your fingers or tweezers. If it's worn or damaged, replace it.


2 Adjust 'the Damper Lever': Properly align 'the damper lever' with the string using a screwdriver or the manufacturer's tool. Compare it with neighboring dampers and inspect 'the damper spring' as well. Replace the broken 'the damper spring' there. We may slightly bend it towards the strings if it weakened and it will work again. This might resolve the issue.


3 Inspect 'the Wippen of the Jack System': Ensure that ‘the wippen and jack system’, responsible for striking the string, are correctly aligned and functioning smoothly. Sometimes, pressing 'the damper spoon' on 'the wippen' slightly towards you can improve more tight damper contact with the string after the key returns to its original position.


4 Align 'the Damper Felt Head': Occasionally, 'the damper felt head' may not align correctly with the strings due to a loose 'the damper screw'. Use a screwdriver with a long, thin tip to gently adjust 'the damper felt head' on 'the damper wire', then securely tighten 'the damper screw'.


If, even after tightening 'the damper screw', 'the damper felt head' doesn't sit flat on the string after the hammer strikes it, it may indicate an issue with 'the wood hole' of 'the damper felt head'. In this case:


1 Remove 'the Damper Felt Head' from 'the Damper Wire'.


2 Find a Suitable Shim: Locate a thin piece of plastic, cardboard, rubber, or similar material to use as a shim.


3 Insert the Shim: Place the shim in the hole of 'the damper felt head' was positioned. The shim creates additional friction between 'the hole of 'the damper block' and the damper wire.


4 Secure the Shim: Ensure the shim is properly installed and secure. Tighten 'the damper screw' to keep the shim in place.


With the shim in position, the damper felt head should now function correctly.
Good luck with your adjustments!