Touch Weight Too Heavy on MX100

[Richard Brekne]

I dont recognize this model number.. but I assume its a small grand diskplayer
??

If so.. it strikes me that these weight figures you report are not sooooo
awfull that you couldnt bring them down to acceptables with a few good old
standard tricks like reducing hammer weight a bit, and protecking the damper
centers. That B7 is pretty darned high but there is usually some easy to fix
cause for the occasional way out of limits key.

I'd first try a few spot checks to see what you can do with regulating and
hammer weight. Check the geometry as well, but you know all that. As for the
friction.. almost looks like you got to little in a few places.. or what ??
Does the action play kinda sloppy ??

Richard Brekne
I.C.P.T.G.  N.P.T.F.
Bergen, Norway

Tom Cole wrote:

> Dear List,
>
> I tuned a Yamaha MX100A (1988) today that had a touchweight problem I
> found curious. It was the first thing the customer remarked about so I
> did some investigation.
>
> I noticed right away that the dampers picked up early but, with the
> dampers picked up by the pedal, the up and down weights were too high as
> well.
>
>   NOTE  DW      UW
>
>         C2      53      34
>         C3      57      36
>         C4      60      36
>         C5      64      38
>         C6      62      38
>         C7      62      39
>         B7      75      41      (C8 felt like it had a mechanical problem)
>
> There doesn't seem to be a friction problem and so the simple solution
> would seem to be to put lead weights in the keys to bring the
> touchweight down but I've never seen a Yamaha that was so out of
> regulation. Is there something about early Disklaviers that I need to
> know? Could this particular instrument have come from the factory that
> way?
>
> Unfortunately, I didn't think to pull out some key sticks to see if
> someone had pulled out the key leads. I did glance down the side of some
> Bs and Es in the bass to check for key leads and didn't see any nor any
> empty holes.
>
> The present owner bought it 3 years ago and the touch was heavy when she
> first got it. So far, two technicians have not been able to help her
> out, one of whom was a Yamaha tech.
>
> Thought I'd run it by the list before getting the lead out. Can anyone
> comment on this weighty subject?
>
> Tom
> --
> Thomas A. Cole, RPT
> Santa Cruz, CA
> mailto:tcole@cruzio.com