THUD

[Roger Jolly]

Hi John,
             Is the rear of the key frame slapping up against the dag??? To
check use a long thin bladed screw driver and press down on the rear of the
frame, whilst playing the note hard. Also the top of the unacorda lever if
it is too long can slap against the top of the keyframe.  Press the pedal
firmly and listen for any changes. Smear a thin coat of white protech
grease on to the top of the lever and check to see if any transfers to the
under side of the frame.
Just some ideas
Roger


At 08:02 PM 21/11/00 -0500, you 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
> 
Roger Jolly
Saskatoon, Canada.
306-665-0213
Fax 652-0505