h'chord LM

[Ed Sutton]

Hi, Dave!
    What would you think of "the jack needs to apply pressure to the string
with the damper, and also just barely be touching the key cloth?"
    I recently attended a talk on harpsichord regulation by Richard
Kingston, which has caused me to rethink these things.  He regulates
harpsichords with remarkable accuracy and ease, and they stay regulated for
years, needing only seasonal adjustment for soundboard and case movement,
which is done entirely by shimming the keyframe and adjusting the jack
registers, and maybe shimming the jack stop rail. He had a harpsichord
returned for cleaning, and after 10 years, the stagger was exquisitely even.
    His technics are obvious, once he demonstrates them. I've not seen them
anywhere else (maybe you have), and fear I would garble them by trying to
describe them in detail. Basically, he regulates from the top of the jack
down, i.e. setting octave samples and trimming the tops of the jacks to
limit key dip from the jack rail.  Then the screw turning can be done on the
bench between straight edges.  He drops the jacks in, and they are all
working!  Because the tops are even at the end of the keystroke, the stress
is evenly distributed and wear and tear on cushions is minimized.
    Hopefully he will give his presentation to a PTG National soon.
        Ed S.
----- Original Message -----
From: "Dave Doremus" <algiers_piano@bellsouth.net>
To: "College and University Technicians" <caut@ptg.org>
Sent: Wednesday, March 19, 2003 1:32 PM
Subject: Re: h'chord LM


> I have just a couple of additions to this:
>
> 1) The jack needs to hang by the damper, if not the damper will not
> work. THis is especially true in transposing instruments.
> 2) Staggering the choirs properly is critial to the touch. This will
> require some lost motion. Often the 4' or the back 8' will pluck
> first, with less lost motion. The front 8' is usually last, requiring
> quite a bit.
> 3) You need to set the first plucking choir so the quills are just
> under the strings (maybe a 1/16), without the dampers involved. Then
> adjust the dampers so that they are on the string when the jack is at
> rest, permitting the quill to slide under the string. Then couple,
> and turn on the 4', and smoothly play the note on the bottom 8', you
> should hear the three plucks distinctly.
>
> 4) Staggering is also affected by voicing, the stiffness of the
> quills will determine when they pluck, if you change a quill or
> revoice, you must check the staggering.
>
> Frank Hubbard has an old good pamphlet on harpsichord regulating that
> might still be available.
>
> Ed is right, if you dont know what you're doing be careful before you
> turn too many screws.
>
> ----Dave
>
>
> -----------------------------
> Dave Doremus RPT
> New Orleans
> algiers_piano@bellsouth.net
> ------------------------------
>
> At 11:13 AM -0500 3/19/03, Ed Sutton wrote:
> >     In a well-regulated harpsichord, the issue is not so much lost
motion
> >between the string and plectrum as "speaking order" of the registers.
The
> >jack should not hang by the damper (except maybe a little in the bass).
If
> >you adjust the lost motion at random you will destroy the regulation of
the
> >speaking order.  If the harpsichord was properly regulated to start, it
is
> >possible to adjust for seasonal rise and fall of the strings by shimming
the
> >back key rail, or in some cases turning two adjustment screws under the
> >case.  This takes minutes, and will not deregulate the speaking order.
> >     If the harpsichord was not properly regulated to begin with, you
need to
> >know enough to know that, and how to do a full regulation.
> >     This is why it is best to take a class on harpsichord regulating
before
> >turning the screws.
> >     Believe me, I now know that I have spent many hours of my life
turning
> >jack screws that I should have left alone.
> >         Ed Sutton, Repentent Jack Screw Turner
> >
>
> --
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