Voicing the GH1

[RndyPotter@aol.com]

Brian De Tar made the following recommendation for solving the voicing
problem at the tenor break of GH1 pianos:

>>First, make sure that the strings are seated at the bridge as well as level
at the "V" bar and agraffes.  To do the leveling at the "V" bar and agraffes,
use a 1/4" brass rod tapered and notched at one end to fit on one string at a
time.  Jim Coleman Jr. has a great tool he sels for this.  I modified mine by
bending it to form a nice handle.  Remove the action and use the tool to
"lift" the strings at the "V" bar and agraffe.

Next, check the density of the hammers with your voicing tool.  Use a
weighted voicing tool fitted with three #8 or #9 needles.  #6 needles are too
big for Yamaha hammers.
Support the hammers with a voicing block before doing any actual needleing.

Use enough force to drive the tool into the hammer so that the tip of the
tool impacts on the hammer head.  This distributes the effect of the needles
a bit farther in the hammer.  What you're looking for is to have the hammers
feel firm but not hard.

HERE'S THE SECRET: The one exception is at the tenor break.  Here, the
tension goes from about 165 lbs. to about 104 lbs. over about 6 notes. That's
a pretty dramatic drop in tension.  If you have Quattro Pro (or Excel) I can
send you a graph of this and other aspects of the scale that you may find
interesting.  I won't get into a discussion as to the pros and cons of this
design.  The fact is what it is so let's enjoy the solution instead of
debating the cause.

So, to get around the drop in tension, we need to make these hammers a bit
softer than the rest.  Start at the first hammer in the tenor and double the
number of stitches you gave the rest of the hammers.  In other words, if you
did 4 stitches on the mid-range hammers, do 8 stitches on the first 6 hammers
in the tenor.  Aim fairly high on the shoulders, about 11:00 on the front
(key) side of the hammer, and about 12:30 on the rear (damper side) of the
hammer.  Go slow and test often.  You won't be able to completely eliminate
the tonal change at the bass/tenor break, but you will be able to get it to
the point that it is more than acceptable.

It probably would make more sense to see and hear this in a demonstration,
and, to that end, we've developed a "show and hear" program to be presented
at conventions and PTG meetings.  I'll be doing an all day seminar in which
this wil be part of the program in Albuquerque the first week in May if
you're in the area. If not, I'm sure you'll get a chance to see it somewhere
soon.
< < End of Brian's monologue


Yet, there is another way.
Rather than do all this to the hammer, to make them so much different from
the rest of the set, and thereby *maybe* get the result you want - consider
changing the strings in those six notes and eliminate most (or at least much)
of the problem?
I learned this from Joe Garrett, Portland Chapter, who evaluated the scale
and designed a string change which takes those first six notes from three
plain wire to two wound strings (you use the two outside pins, leaving the
*former* center string's pin naked), which does a very, very good job of
blending the tone of the center into the bass, and requiring only very minor
poking and shoving of the hammers.
And because of the tension changes, once the new strings have settled in they
tend to hold pitch better than the plain wires did.
Joe shared this with Yamaha, who had replacement strings made, and
technicians like myself have ordered them from Y in the past and installed
them on GH1s. (Several years ago they turned the production and supply of all
non-current / out-of-warrantee (i.e. over 10 years old) strings to Schaff, so
I suppose that is whom you would call for them now.
A few years later, Yamaha rescaled the instrument, and the newer version does
not have the same condition.

Brian DeTar, who does a lot of work for Yamaha and has probably serviced more
Y's than I will ever see, probably knows more about the peculiarities of the
various models of their instruments and hope to, and I am sure that his fix
is sound. If it did not work, he would have figured something else out.
When you are the troubleshooter guy, you develop systems that work in the
quick, because that is what you need. In the situations he often works, he
may not always have the luxury most technicians have, that of saying "gee, I
need to order some parts, be back in a week". But we can do that, and I
recommend you give this one a try.

If you have any trouble getting them from Schaff, you can write Joe Garrett
and he will send you the specs you need in order to have them made by your
favorite string maker.
Joe Garrett, R.P.T., is listed in the current PTG Directory, and has been at
the same address for the 20+ years I have known him (though the county
recently gave them street addresses, it is the same place).
If you do not have the PTG Directory, do yourself a favor and join PTG - and
they will send you one "free" with your paid membership. Such a deal.

Randy Potter, R.P.T.