THUD

[Daniel Gurnee]

on 11/21/00 5:02 PM, John D. Chapman at chapmajd@wfu.edu wrote:

> Just tuned a S&S D brought in by the dealership for a Brahms concerto with
> the symphony.  Notes 50,51,52,&53 (last four in agraff section, just above
> A440) had an unpleasant pronounced THUD when played above forte.  This is
> the same THUD which is always there lurking behind piano tone but usually
> not dominating it.  I checked keyframe front, back, and glides, checked
> for loose hammers, held up dampers heads by hand and played the note to
> see if it was a damper problem and it was  not, checked damper upstop
> rail, seated strings on bridge, reshaped hammers to that nice S&S pointy
> shape, tried needling, tried juicing, switched a couple of hammers from a
> few notes below where the sound is good just to see if it was a hammer
> problem and it was not.  What have I missed?  The one thing I didn't do
> which might have help diagnose the problem was to pull the action in and
> out to change the strike point.  What do you think?
> 
> John D. Chapman RPT
> Wake Forest University
> Winston-Salem NC
> 
> 
John D. Chapman,

The "bell" at the treble end under the case can affect the tone in more than
the immediate area. It must not be used to adjust bearing, but taken up
unloose to snug.

Many excellent suggeations.

Daniel Gurnee, RPT