Pitch Raise Stability, was Oops?

[Farrell]

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"But let's take a piano that is 1/2 step flat in the midrange.  That's =
100%.  Very often, such a piano is not evenly low in pitch.  The high =
treble may easily be 150% flat.  Now add 30 cents for the high treble =
for the usual amount of stretch.  We're up to 180% now, which =
theoretically would take +60 cents overpull."

What is all this percent stuff? Do you mean cents?

"It all adds up to a claim that I would really like to see =
substantiated:  a 100% pitch raise in 2 passes that comes out "dead on". =
 I'm not from Missouri but *show me* anyway."

I guess it depends on what you mean by "dead on". The original statement =
was "With the Sanderson Accu tweaker(as Jim Harvey calls it), and a good =
ear, I can pitch raise a piano 100 cents low, in two passes and get it =
dead on A440." I think this pretty clearly is making the claim that A4 =
ends up at 440 hertz. I would imagine that the claim is also being made =
that the rest of the notes are close enough for a final tuning pass. =
That being the case, I do that routinely. I don't like to raise a string =
more than 25 cents above its targeted frequency (I like to keep it a lot =
less than that actually). For a 100 cent flat piano, I would do a first =
pass overpulling the bass by about 5 cents, the tenor about 10 cents, =
and the treble about 15 cents (if the piano is old and crusty I would =
first pull the treble to target pitch, and then go over it a second time =
targeting pitch again). On my second pitch raising pass I would use the =
SAT-calculated overpulls (a little less in bass) and pretty easily end =
up within a cent or two of targeted pitch. Prior to the second =
pitch-raising pass I would typically find the piano 10-15 cents flat in =
the bass, the tenor about 20 cents flat, and the treble perhaps 30 cents =
flat. After the second pass, I would most often be ready for a tuning =
pass. Sometimes the magic does not work quite so well, and I will either =
have to do a third pass to get it close enough for the tuning pass, or =
perhaps just adjust a couple octaves before the tuning pass. The top =
couple octaves is what usually suffers the most (but do people with =
100-cent flat pianos play up there???).=20

But most often, two pitch raising passes and then a tuning pass for the =
100-cent flat piano. This certainly won't be a concert-level tuning, but =
part of my thinking here is that no matter what you do to the poor =
neglected piano, it will not be a very stable tuning when you are done, =
so trying for tuning perfection may not be of great benefit here. Rather =
than trying to get the perfect tuning, I tend to spend a bit of time =
during the pitch raise (especially on the second pitch-raise pass) =
trying to make sure the back scale string segments get stretched out and =
the string is not dropping in pitch under firm blows. I guess that is my =
philosophy on such a piano - get it up to pitch, get it as pitch-stable =
as is possible, put a tolerable tuning on the piano. I'll commonly spend =
about 105 minutes doing the two pitch raise passes and one tuning pass. =
Maybe a bit more if the Goddesses are not smiling on me that day.

One thing I have noticed when doing the BIG pitch raise is that after =
getting the upper treble up to pitch, often you can observe the =
instability. I'll give a note a few firm blows to make sure it is not =
dropping in pitch, and then put it where I want it. Hit the key hard, =
the pitch drops. Hit the key medium light, the pitch goes sharp. Hit it =
hard and it goes flat again, play it medium and it goes sharp. You can =
vary the pitch easily by two to five cents up and down, up and down, =
just by how hard you play the note. When I see that kind of stuff after =
the big pitch raise I feel pretty confident that no-way are you going to =
get a real stable tuning on that piano on that day.

And that's all I got to say 'bout that.

Terry Farrell
  ----- Original Message -----=20
  From: Billbrpt@AOL.COM=20
  To: pianotech@ptg.org=20
  Sent: Monday, November 05, 2001 7:35 PM
  Subject: Re: Oops?


  In a message dated 11/5/01 6:16:31 PM Central Standard Time, =
davidlovepianos@earthlink.net (David Love) writes:=20


    Also, so that those who are not familiar with your style of tuning =
are not mislead, the standard pitch raise function should get the treble =
sharp enough if you measure/reset frequently on the way up and if you =
are using standard stretching.  I recall that you mentioned that in your =
tempered octaves tuning you are +75 cents by the time you get to C8.  =
Those tuning with normal stretch are more likely to reach only +40.  For =
your system that would require additional stretch going up.  For others, =
they would end up considerably sharp of the target and have to do a =
lowering before a fine tuning.


  Yes, but bear in mind that most of the time I use a more conventional =
amount of stretch.  The triple octave/double octave and fifth comparison =
is only for when I wan the absolute maximum and justifiable amount.  =20

  Once I get into the last part of the 7th octave, all bets are off.  =
But let's take a piano that is 1/2 step flat in the midrange.  That's =
100%.  Very often, such a piano is not evenly low in pitch.  The high =
treble may easily be 150% flat.  Now add 30 cents for the high treble =
for the usual amount of stretch.  We're up to 180% now, which =
theoretically would take +60 cents overpull.  Yipes!=20

  Maybe on a new or newly strung piano but even then, I'd prefer to work =
my way up.  The danger of breaking a string or splitting the bridge on =
the poor old Betsy Ross is simply too great.  Add to that the kind of =
test blows needed to settle such a change and you'd be bustin' those =
elbows or breaking the keys themselves at the balance rail.=20

  It all adds up to a claim that I would really like to see =
substantiated:  a 100% pitch raise in 2 passes that comes out "dead on". =
 I'm not from Missouri but *show me* anyway.=20

  Bill Bremmer RPT=20
  Madison, Wisconsin=20

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