RE Damper Wheeze

[Kenneth Sloane]

                      Subject:                              Time:  10:47 PM
  OFFICE MEMO         RE Damper Wheeze                      Date:  2/7/95

                    --ORIGINAL POST--

Anybody have tricks on getting rid of damper lift noise in the trichord
wedges. I was called in at a fancy recording studio, whose Yamaha C7F
Disklavier had a noisy sustain pedal. The dampers in this region (16 in all)
have trichords front and back, ruling out the chance of a Steinway style
solution (favoring the flats over the wedges). My first idea was to replace
the back wedges with flats. Mark at Yamaha said try trimming the portion of
the wedges which hang underneath the string and to iron the sides of the
wedges (to smooth down any stray fibers which might be sticking out. Neither
of these worked. The only thing which did was the introduction of the flat
pads (and that works to the extent that you leave the balance of pressure
between the front and back towards the side where you begin to notice the
softness of flat-pad damping.) Of course, they can also pull the mikes out
from under the lid, and make sure that when it comes time for the quiet
passages which will show up the "heartbreak of damper emphysema", the pianist
has the sense not to approach the sustain pedal as a hot-rodder would pealing
out on a green light.
Any ideas?

Bill Ballard RPT      "May you work on interesting pianos."
NH Chapter, PTG               Ancient Chinese Proverb

                       -- REPLY --

The older Yamahas used trichord wedges made of felt with a vertical grain
orientation. It was very easy to get positive damping with this felt
initially, but it became string cut rather quickly and was more problematic
with the wheeze (I've heard the  term whoosh used, also) when using the
sustain pedal. Does your piano have the vertical grain wedge? If so, get rid
of it. Yamaha can now supply you with a trichord wedge made with felt with a
horizontal grain orientation. The felt has a good density (not too hard and
not too soft so it damps pretty well but lasts fairly long) and also has a
good shape so it fits into the strings well. Also, polishing srings with
polita might alleviate some of the problem.

Ken Sloane, Oberlin Conservatory