Agraffes on Bridge

[Don Mannino]

Jim,

I have restrung a couple of these pianos.  I did not do any measurement of
the string scale to check for speaking lengths, but I had no difficulty with
the tension or tuning them up to pitch.  Perhaps the new strings kept things
workable.

When the pianos are in good shape (after rebuilding) there is no question
that the tone changes at the treble break, where the bridge agraffes stop
and the standard bridge begins.  I had to compensate pretty dramatically
with the hammers to even the tone.  In the bridge agraffe section the pianos
had a very clear and clean tone, with strong high harmonics.

Don Mannino


> -----Original Message-----
> From: caut-bounces@ptg.org [mailto:caut-bounces@ptg.org] On 
> Behalf Of James Ellis
> Sent: Wednesday, June 23, 2004 7:41 AM
> To: caut@ptg.org
> Subject: Agraffes on Bridge
> 
> 
> I was going back over some old CAUT postings that I had saved 
> for future reference, and I came across one by Otto Keyes on 
> April 8, 2004.  Otto mentioned a 5'7" Sohmer with agraffes on 
> the main bridge.  He mentioned that the piano had a "brassy" 
> sound, and attributed it to the brass agraffes on the bridge. 
>  I don't think that is the reason for the brassy sound.
> 
> I recently encountered one of these old Sohmers - a 
> 100-plus-year-old 6-ft that had recently been refinished and 
> restrung.  It was in an expensive house in a very up-scale 
> exclusive area out on a lake - fenced, gated, private boat 
> dock, and all that stuff.  It was to be used for a formal 
> recital with several other instruments - strings and 
> woodwinds.  The owner told me the piano had been kept tuned, 
> nevertheless, it was quite flat when I found it.  I knew it 
> had been designed for A=435 Hz, but all things considered, I 
> thought it would come up to A=440 OK.  I was wrong.
> 
> In doing the pitch raise, I did NOT over-pull on this one - 
> not on a piano this old with an unknown history.  
> Nevertheless, when I got up into the treble, strings began to 
> break.  Then it dawned on me:  Just eyeballing it, the 
> speaking lengths of those treble strings looked abnormally 
> long to me. I did some measuring, and indeed whey were.  The 
> speaking length of No. 88 was like 2.5 inches, and A5 was 
> like about two inches longer than on most modern pianos.  
> With this in mind, I concluded that there was no way this 
> piano was going to come up to A=440 without breaking treble 
> strings all over the palce.  In fact, it was pushing the 
> limit even at the A=435 Hz.
> 
> And that's not all.  I measured some wire sizes.  The entire 
> top two octaves were strung with #12.5 wire.  As I say, it 
> had been restrung. Whatever the original size wire was, I don't know.
> 
> I had to inform the owner that I would put the piano at its 
> design pitch of A435 Hz, and she would have to make other 
> arrangements regarding the recital.
> 
> I could not find any evidence that any bridges or the plate 
> had been moved from the original positions.  So, I'm thinking 
> that "brassy" sound Otto was hearing may have been due to the 
> scaling of the piano, and not to the agraffes themselves.
> 
> One other point:  The construction of that bridge, with all 
> the strings elevated right behind the agraffes, is bound to 
> make the bridge want to roll toward the rear - strings 
> pulling up on the agraffes in front, etc. 
> 
> I would like to know who else out there has run into similar 
> situations with these old Sohmer grands?
> 
> Sincerely, Jim Ellis
> 
> 
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