Teacher's piano problem

[Jim_Harvey@yca.ccmail.compuserve.com]

Avery,

I'm just returning from another extended service outing. As a result
of backed-up mail, I've been able to read all the replies to date on
this post. Until said road trip, I wouldn't have the following
(possible) answer to this situation.

Same factors: teacher's piano; 'chiff' on damper, not hammer rise.
Different factors: Piano is Steinway, not Baldwin; effect is on
trichords, not bichords.

Teacher had been complaining for some time about this phenomenon, Due
to differences in our nomenclature, I had undoubtably been listening
to the wrong phenomenon. I'm familiar with 'pfffft' and 'whoosh', but
'chiff', as in pipe organ vernacular, had not been used to describe a
piano phenomenon before. On each service call, I would try different
things. Teacher was exercising patience with piano and me. Mine was
running out. Finally I heard the *exact* thing at the *same* time as
teacher, by having TEACHER play the key instead of me.

As simple as the cause and repair turned out to be, describing it with
words may be tough. Consider that trichord (or bichord) dampers consist
of two parts, the forward and rear. Each of these in turn has
individual front and rear components. This nets a total of four
contacting surfaces. In my case, several of the innermost rear damper
"components" (3rd damper component back from player, and the most
difficult to see), had glue-starved bonds on *one* side of *one*
damper. [No, I don't know how this happened].

The resulting effect was that the trailing edge of these dampers were
not clearing the strings at the same time as the others. Indeed, the
'stagger-back' effect was causing a 'chiff' effect, and it was due to
the dampers; not hammers, voicing, strings or soundboard/other.

Even though one of my prior diagnostics procedures involved the use of
an inspection mirror to view the dampers, I somehow had missed seeing
this. In retrospect, I believe I was exercising the key in a playing
mode, not a diagnostics (slow-motion) mode. Apparently, the 'Velcro'
effect of the felt would cause the damper to adhere in certain playing
modes, but not in others.

I hope this bandwidth is of some significance in some instance, if not
this one.

Jim Harvey, RPT
____________________________ Reply Separator __________________________
I have in my studio a 7' Baldwin, purchased about 4 years ago.  It has
what I call "organ pipes" in some, but not all, of the bass notes.
That is, at the initial tone there is a "pfffft" sound, which reminds
me a little of the mechanical sound of an organ pipe.  It doesn't
happen on each note. Could it be some type of overtone caused by the
damper exciting the string upon playing?