One thing that comes to mind, especially if the jacks are plastic. If 
the jack body has a projection to hold the damper, often that is the 
culprit. As the jack returns to rest, the projection holding the damper 
thunks on the top of the register.
Dongsok

On 10/16/2017 2:05 PM, Chris Vandekerkhove wrote:
> Dear members,
>
>   
>
> I'm reviving an elder harpsichord. What still troubles me is the sound I
> hear when the jack comes back down on the keyboard: there is a definite
> "thunk" to be heard. They keys have felt on them but maybe the felt is too
> old? Any ideas how to solve this. FYI there are screws on the bottom of the
> jacks.
>
>   
>
> Greetings,
>
>   
>
> Chris.
>
>
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::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
Note:  opinions  expressed on HPSCHD-L are those of the  individual con-
tributors and not necessarily  those of the list owners  nor of the Uni-
versity of Iowa.  For a brief  summary of list  commands, send mail to
[log in to unmask]  saying  HELP .
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::