post pitch-raise creep?

[Bob Hull]

It's interesting to hear someone else talk about
spending more time in the pitch raise sometimes than
in the final pass.  I have also found that sometime I
can get through the final pass faster than the pitch
raise if I am fairly careful doing the pitch raise/or
pitch lowering.  
My pin setting during the pr is basically just going
slightly above the pitch I want, and making sure I
feel the bottom of the pin move in the block, and then
easing it back down to the desired pitch.   
 
I am experimenting between fast and sloppier pitch
raises versus careful ones to see which I really like
best in terms of time and final accuracy.

Bob Hull
 




--- "pmc033 at earthlink.net" <pmc033 at earthlink.net>
wrote:

> David:
>     Since different techs use different pin setting
> techniques, it's hard to say exactly how much over
> pull will work for every situation.  During the last
> few weeks, there was a discussion of overpull
> percentages with RCT users.  Some had to adjust the
> overpull because their pianos were coming out too
> sharp using the default percentages.  
>     For years, I had been using my SAT for pitch
> raises using the single string method described in
> the SAT manual.  That is, doing the unisons at the
> end.  I would pull the bass 25%, and mentally
> calculate the rest of the string overpull at 30%.  I
> would carefully set the pins as close as I could. 
> After pulling the unisons in, I would end up sharp
> in the low tenor, less sharp in the rest of the
> tenor section, and the treble came out ok.  I used
> to reduce the overpull in the tenor accordingly
> (lots of mental gymnastics here).  It seemed to work
> for me.  
>     Then, I got the Pocket RCT, and began doing
> unisons as I went along.  I found that doing this
> produced a more accurate result.  After a few months
> of PRCT, I went back to my SAT and began using the
> string by string method.  The result was that my SAT
> pitch raises began to come out much closer to pitch
> than before.  Since the SAT has a default 25%
> automatic overpull, I use that in the bass.  In the
> low tenor, I use 25% also, maybe adding a few cents
> more (maybe closer to 28% overall).  Starting in the
> treble, I go back to 30% for the rest of the
> strings.  
>     I spend much more time in the pitch raise than
> the final pass because I find that the result is
> much closer if I do that.  If I spend less time on
> the pitch raise, not being as careful, I have to
> spend more time on the final pass.  I do set the
> pins  while pitch raising.
>     Doing the unisons string by string may seem
> tedious (which is why I resisted doing so for
> years), but the result is more accurate in my
> experience.  YMMV.
>     Just my $.02.
>     
>     Paul McCloud
>     San Diego
> 
> 
> ----- Original Message ----- 
> From: David Nereson 
> To: Pianotech List
> Sent: 07/09/2006 4:58:54 AM 
> Subject: RE: post pitch-raise creep?
> 
> 
> 
> -----Original Message-----
> From: pianotech-bounces at ptg.org
> [mailto:pianotech-bounces at ptg.org]On Behalf Of
> Farrell
> Sent: Friday, July 07, 2006 6:04 AM
> To: Pianotech List
> Subject: Re: post pitch-raise creep?
> 
> 
> Doesn't sound right. When doing the PR, are you
> using an ETD?  
> 
> Only to measure the amount it's flat and to tune the
> initial A4 sharp by 40% of the amount it was flat.  
> 
>  Unisons as you go?  
> 
> No.  All the middle strings, then all the unisons,
> then the bass, which sometimes needs very little
> raising.  I can do it fastest that way.    
> 
>  41% is very large percentage for overpull. Most
> ETDs recommend between 20% and 35%, depending on the
> area of the scale. 
> 
> And I say that's usually not enough.  If it's 20
> cents flat, half of that (50%) is 10 cents, and a
> third of that (33%) is about 7 cents.  So I pull A4
> halfway in between those numbers, or about 8 1/2
> cents sharp, which is roughly 40% of the amount it
> was flat.  (I notice in other posts, some tuners use
> up to 37% in some areas of the piano.)  Then I do
> the pitch raise, all the octaves, then all the
> unisons.  Almost every time, A4 ends up right on
> 440, and the rest of the rough tuning is very close.
>   So I go ahead and do the tuning (fine tuning). 
> It's after I'm done with the fine tuning, when I go
> back to check for anything that has slipped, that I
> find the middle of the piano and the low tenor has
> crept sharp by a beat or even two.  
> 
> Immediately after the PR, do you check the middle
> section for pitch?  
> 
> Yes, and it's almost always right on 440, so I
> proceed with the fine tuning.  It's after the fine
> tuning that I find it has crept sharp in the middle.
>  The low tenor is also quite sharp, so now I leave
> that area a bit flat during the pitch raise.  And
> during the tuning (fine tuning), the SAT always
> seems to "tune" the bass too flat, even if the bass
> didn't need a pitch raise.  
> 
>  If it is at or near target, there is no reason for
> it to creek up.  
> 
> One wouldn't think so.  
> 
>  How large a pitch gain are you talking about?  
> 
> Anywhere from just a few beats flat to a half-step
> flat.
> 
>  I've never noticed such a phenomena.
> 
> That's "phenomenon."  Phenomena is plural.  (Just
> for your own info.)
> --David Nereson, RPT
> 
> Terry Farrell
>     


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