Muffler Rail on Kawai ST-1

[jimf12]

I have a 2020 Kawai ST-1 that I just had tuned yesterday.   There were some issues with the tuning, and I am having the technician come back tomorrow.   One of the issues is that the action is being affected by the muffler rail felt.   What is happening is that even when not engaged, the hammers are still making contact with the felt when striking the string.   The real problem occurs when the hammer returns, when playing softly the hammer sometimes will get caught on the felt and does not properly reseat itself.   The next strike of that key is not what you expect in terms of feel or dynamics.    Just lifting the rail a small amount gets the felt out of the way, so I am sure that a small adjustment there is all I need.    Am I correct that this is just a simple adjustment?   

Also, any harm in just telling the guy to take it out completely?   I do use it occasionally when doing scales/exercises, otherwise never.   I have had an issue with a slight buzzing noise when hitting C# that comes and goes, and sure enough it wasn't there yesterday when the technician was here but it is back today.   I'm thinking with the spring, screws etc.. for the muffler rail it's just more possible sources of problems like that.   Do they cause more problems than they are worth?   

[themaximillyan]

HI, jimf12

If I understood you correctly, then there was an imbalance in the operation of the 'muffler rail felt'. This unfortunately happens, but there is no tragedy in it I'm think. You can try to fix this yourself. What I think is needed is to slightly raise the edge of the felt strip there. If the wood rods going to the 'muffler rail felt' have connections, then you just need to  fill it out  space in 1cm. or a little more cardboard there. Cut out circles from cardboard and make a cut along the radius so that you can put it between the felt shim and the wooden rod.
As for the sound of the (C#) wich buzz there, shoot a 1-minute video, where you can see, if possible, the strings and the work of the hammer there too.

regards, Max

[jimf12]

Thanks Max - issue with the muffler was resolved, and we could not reproduce the buzzing.   If that comes back, I will take you up on your offer of analyzing a video.

[themaximillyan]

Me glad that it's work,
regards,