Is A440 too much tension for old pianos? (was Old Bosie)

[Ron Nossaman]

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>I'd like to know whether any pianos can't take the tension of A440 ("A435"
>cast into the plate is a good sign, I understand)...

You don't KNOW that ANYTHING can take 440 tension until you pull it up and 
find out. You can only presume that you think it ought to if it was 
originally built for the tension loads the original scale put in the 
original distribution across the plate, or if it was overbuilt enough to 
take the difference. A quick check of one particular scale shows total 
computed tensions of 45,790 lb (20,770 Kg) at A=435, and 46,849 lb (21,250 
Kg) at A=440, or about a 2.3% tension increase. A given piano can have 
wildly different tensions with different scaling. If the piano was restrung 
at some point, you really don't know what the original tensions were to 
begin with, since you really don't know what the rebuilder or the string 
winder might have changed or for what reason. With every piano you will 
ever bring up to pitch, regardless of it's age, design, and general 
condition, you either pays your money and takes your chance, or take what 
you think you can safely get and tune it at what you consider to be an 
appropriate pitch. Your call, or more appropriately, the owner's.

Check the archives for all the gory details of speculation.


>The complications I refer to are those during a pitch raise, where bringing
>strings up to tension affects the pitch of strings you've already tuned.
>Obviously you have to do two (or more) passes, but what's the best sequence
>to get to stability fastest?  (I should have looked in the archives first).
>
>--Cy--

How deep is a hole? It depends on whether or not you have to dig it 
yourself and what kind of shovel you will use. Aural tuners use different 
shovels than ETD tuners, and ETD tuners use different ETDs with which to 
shovel, so the "best" method is what works well enough for (name on 
request) tuner, by (name on request) method, on (name on request) piano, 
that the method in that instance was good enough to produce the required 
hole. Almost any process works well on Yamahas, and nothing works on 
Kimball consoles no matter what you do, regardless of who is shoveling 
what. If you use an ETD, take advantage of the R&D that went into producing 
it and use the supplied pitch raise routines.

Ron N

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