Buzzing soundboard

[Ed Carwithen]

All right my friendly wizards:

th piano is a Chickering Grand, about 4'7" I think.  Piano Atlas has it
manufactured in 1908.  It was Rebuilt in 1995.  Guy did a nice job on most
of it, but some problems with which I have been dealing for the past 3 years.

There was a bit of a buzz on some notes, especially Bb5 and A5, also Bb 4.
We haven't been able to eliminate it.  I investigated all rattly things,
but no much help.  The client discovered that pressing on the sound board
behind the upper treble caused it to diminish.

There is a round nut that goes through the soundboard that has two small
holes for tightening.  It is under the F#5, G5 strings, between the bridge
and the string termination.  I had to loosen the strings to get at it, but
it was loose, so I tightened it.  No improvement.  There is another nut
just like it under the A1 strings in the bass, and the lower treble strings
that cross under the A1 strings.  I didn't try to tighten that nut, but it
might also be loose.  

The buzz is worse than it was the last time I worked on the piano, and is
really unacceptable.  Pressing on the soundboard does almost eliminate it.  

When the rebuild was done, the bridge structure was not replaced exactly.
Pretty close, but the E5 treble string actually touches the plate.  I don't
know if this is part of the problem.  It didn't seem to make a difference
when I loosened this string, or put felt between the string and the plate,
so I took it out again.  

Any ideas as to where to go from here???


Ed Carwithen
John Day, OR