Help regulating sostenuto

[Michael Spalding]

Paul and LIst,

I'm sorry, I guess I was not clear about the nature of my question.   The
sostenuto tabs are the non-pivoting type.  Therefore, if the sostenuto
blade is supporting dampers at the same height as the key-lift, then keys
played while the sostenuto is activated will encounter increased resistance
before the key is fully depressed.  The top of the sostenuto tab on the
note being played will contact the bottom of the sostenuto blade.  The key
will be trying to lift the damper to a height such that the bottom of the
sostenuto tab is even with the top of the blade, but it will be trapped
beneath the blade.  Something will have to give.  Are these non-pivoting
tabs supposed to flex enough to let this happen?  Is the player just
supposed to put up with this added resistance?  Hope the question is now
more clear.

thanks

Mike


> [Original Message]
> From: Paul McCloud <pmc033@earthlink.net>
> To: spalding48@earthlink.net, Pianotech <pianotech@ptg.org>
> Date: 12/17/2005 9:37:21 AM
> Subject: RE: Help regulating sostenuto
>
> Mike:
> 	It sounds like you need to limit the travel of the sostenuto linkage so
> that the blade doesn't lift the dampers higher than key-lift height.  
> 	Having said that, it could also be that the sostenuto blade isn't at the
> proper angle at rest.  If it's too close to horizontal (viewed from the
> end), it will lift too high  when in use.  Set it about a 45 degree angle
> at rest, or whatever angle it needs, so it's not lifting the dampers too
> high when the pedal is fully depressed. Limit the trapwork movement
(adjust
> capstans or install felt blocks above the lever) so the sostenuto rod
> doesn't turn too far. Set the height of the sostenuto rod so that the
> sostenuto tabs peek above the blade about 1/16".  Set the proximity of the
> blade to the tabs so it's not too close or too far by adjusting the
> brackets in or out.  I don't know the Knabe configuration, but the Asian
> pianos have brackets screwed into the bulkhead.  Yours may be held by
posts
> in the keybed.  
> 	As far as the upstop rail is concerned, you need to set it by using a
> black key fully depressed.  Leave a very minimal travel of the damper
while
> the key is depressed.  It's ok to have the dampers lift minimally,
assuming
> the damper felt fully clears the strings.  If your trapwork is properly
> adjusted, you won't have a problem. 
> 	I hope this isn't as clear as mud.  Good luck!
> 	
> 	Paul McCloud
> 	San Diego
> 	
>
>
> > [Original Message]
> > From: Michael Spalding <spalding48@earthlink.net>
> > To: Pianotech <pianotech@ptg.org>
> > Date: 12/17/2005 5:58:52 AM
> > Subject: Help regulating sostenuto
> >
> > It's an old Knabe with non-pivoting tabs.  Regulation accomplished so
far:
> > 1.  Dampers lift evenly from keys.
> > 2.  Dampers lift evenly from pedal, not quite as high as from keys.
> > 3.  Sostenuto picks up dampers from either Key-lift height and raises
them
> > above Key-lift height so that when additional notes are played, the top
of
> > those tabs don't hit the bottom of the sostenuto blade.
> >
> > I'm happy with how all of that is working, but the problem is in setting
> > the damper upstop rail.  When high enough to leave room for sostenuto
> > operation, it's too high for normal playing.   Or I could set it for
> normal
> > playing, compromising touch when the sostenuto is in use.  What do you
all
> > do?
> >
> > thanks
> >
> > Mike
> >
> >
> > Michael Spalding
> > spalding48@earthlink.net
> >
> >
> >
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