THUD

[John D. Chapman]

Ron,
I did check the rep window felt, but will double check the action rails.  
The thud is a percussive slap heard to some extent behind all piano
attack, but very pronounced in these four notes above a forte blow.  I
might also say that in addition to the thud being more pronounced for
notes 50-53, the rest of the piano's tone for those four notes is weaker.
John

On Thu, 23 Nov 2000, Ron
Torrella
wrote:

> **I originally sent this yesterday morning, but the server must've eaten
> it....
> 
> Check the action rails--especially the joint adjacent to 50-53 on the
> hammer
> flange rail. Also, check those particular wippens. Is there sufficient
> felt at
> the frnt of the window to keep the jack from slamming into the rep
> lever?
> 
> Have you been able to localize the sound of the thud? Describe that.....
> 
> Ron Torrella, RPT
> "John D. Chapman" 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
> 
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