Supplamental technique study for fine tuning unisons (long) The odd thing is...

[Dan & Martha Reed]

List,

     For a few years, I have been actively experminting with trying to
accuratly set unisons with techniques in addition to hammer technique. The
reasons I have searched for additional methods, have to do with the
limitations of my hammer technique, to be sure...but, never the less, some
pianos resist fine unison setting. Some fellow technicians (famous people!)
are also experminting and using string stretching tools to change the pitch
a little.
     The reasons some pianos are difficult in this area of fine unison
setting are numerous and vaired, and should be studied in order to better
understand the cure.  But please allow me to move on to the strange reaction
I am getting from one technique.

The problem:

A three string unison (solid wire) which is not clean...

   In setting the three string (solid wire) unison, for purposes of this
example, mute the left wire, so as to hear only the middle and right wire.
Again, for this example, we determin that the right wire is slightly sharp.

The technique:

    Using a 1/8 th.inch diameter brass dowell, with a modestly tapered end,
with a rounded (smooth) grove cut into it, I 'rub' the wire like I am trying
to polish it. Five of six strokes will lower the pitch. In the middle of the
piano, a unison which is one or two beats high, can be coaxed down with this
technique, usually in one (six stroke) pass.
    On some wire, one can feel 'bumps', where the wire is either slightly
bent, or just unevenly drawn. I think to myself that I am 'strightening out
the wire' with this technique, because the pitch comes down. ( I try and
avoid pushing down on the wire, so as not to introduce excessive distortion)

One other wire, there is quite a bit of resistance from corrosion.

The odd thing is, that the pitch comes right back up. Just strike the note,
and hear it start to go sharp again. After four or five hard blows, it is
back to (about) where it started before massaging. (I am an aural tuner, and
I check the individual wires with thirds or sixths. It is the massaged wire
that is comming back up, and not the other wire going south.)

Just when I thought I had found a nice accurate controlable method to subtly
change the pitch to clean up a unison!

Dan Reed
Dallas Chapter