Article about bridge agraffes - function, types

[Calin Tantareanu]

Hi Ron! 

> -----Original Message-----
> From: pianotech-bounces at ptg.org 
> [mailto:pianotech-bounces at ptg.org] On Behalf Of Ron Nossaman
> Sent: luni, 20 noiembrie 2006 00:26
> To: Pianotech List
> Subject: Re: Article about bridge agraffes - function, types

> 
> Hi Calin,
> Keep in mind that the wood isn't the termination in a standard 
> bridge configuration. The pin is, and as long as the pin is 
> solidly embedded in the wood at the cap surface, It is very 
> nearly as efficient a termination as an agraffe. That's why 
> some of us have gone to laminated bridge caps.

Yes and no. I think that as long as the string touches the wood cap because
of downbearing, it will influence the sound of the string too, and is likely
to diminish the efficiency of the termination as a whole (more or less,
depending on how stiff that wood cap is). 
 

> I think you may be missing the point. You gave a weight of 
> 18.2 gr each for Steingraeber agraffes, of which the 
> accompanying photo shows 16 in the top treble section. The 
> agraffes weigh in at 291 gr all by themselves in that section 
> alone, which is around twice the mass load I'd typically 
> install in a conventional bridge in that section. The Stuart, 
> etc, aren't that heavy, but still add up to a significant 
> mass, which is the reason for the increased sustain, not the 
> termination quality. Having listened to sustain times before 
> and after the addition of mass to treble bridges with no 
> changes to the pinning, I can assure you that mass can rather 
> dramatically extend sustain times.

Interesting. I can't tell how much of the improved sustain is because of the
added mass and how much because of the improved termination quality of the
agraffe.

> I expect that most of us doing design modifications with 
> rebuild have at least one bridge agraffe design we're looking 
> for an excuse to throw enough cash at to try out in a real piano.

So what would yours look like?

Calin Tantareanu
http://calin.haos.ro
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