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

[Richard Brekne]

Hi Cy, I will defere any exacting tension figueres to others, but I
think one can safely say that the less stress you place on an older
instrument, the safer off you are in avoiding overstressing it. 

Most older instruments really need a full revamp from bottom up if they
are to present the origional design strength against the design tension.
Obviously, the market simply doesnt generally support the kind of work
neccessary, and you get immediatly into the discussion of old wood vs
new wood in all its variant glory, and a host of other issues as to the
point of such repair as well. So that generally leaves us with
instruments that are somewhat structually weakened relative to their
condition when new. How much so is most often impossible to be sure of.
So.. I like to recommend people play it safe, rather then wake up sorry
one fine morning.

Cy Shuster wrote:
> 
> 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)...
> 
> 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).

Yes, that what I thought... you are definatly going to find some
discussion as to the whys, and how muches of that issue. But Reyburn and
others claim that pitch fallback is most predictable if you start at A0
and proceed chromatically up. Maybe it works just as good from C8 down
chromatically as well.. dunno. For whatever reasons.... it appears to be
such, at least to some degree in enough instances that its programmed
into pitch raiseing routines for these ETD's of ours.

> 
> --Cy--


Cheers
RicB