THUD

[Horace Greeley]

Steve & John,

Yes - I've also heard a loose rib make these kinds of nasty noises.

Along the lines of Steve's second question,  I had a very illusive one 
years ago (on a B) which turned out to be the bridge pins binding against 
the under side of the plate (you know where) when the humidity was just 
right.  The thing that made that one hard to find is that I never found an 
intermediate point (humidity-wise) at which it would simply buzz...just 
thud, or fine...thank you very much.

Curiouser and curiouser...

Horace



At 06:17 PM 11/21/2000 -0800, you wrote:
>John,
>
>If you find it isn't a keyframe/shift lever noise, check to see if the
>sound gets better when you put firm pressure on the bridge cap at the end
>of the section. If it does, let down the tension on those notes and
>you'll probably find a loose glue joint between cap and bridge body.
>
>Another thing to look at is clearance between the bridge and the plate. If
>the bridge is touching the plate, you'll get a very strange sound.
>
>Good luck,
>
>Steve
>
>
>
>On Tue, 21 Nov 2000, 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
> >
> >
>
>
>_________________________________________________
>
>Steve Brady, RPT
>Head Piano Technician, University of Washington
>Editor, Piano Technicians Journal
>
>
>