Article about bridge agraffes - function, types

[Ron Nossaman]

> I'm sure mass added to the treble bridge has an important effect. What I'm
> trying to say is that after one has applied the necessary mass, the bridge
> cap/pin is still a place where energy is lost. A bridge agraffe would help
> there, by wasting less energy than the traditional termination.

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.


> Mass loading and bridge agraffes are not mutually exclusive piano design
> elements. They should work very well together.

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.


> I have seen it before and find it a very good idea. I hope you'll experiment
> with bridge agraffes too, because it seems to me they have great potential,
> even if they induce new tonal aspects in piano design.
> As you saw in my article, there are ways of making them more or less
> complicated.

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.


> I really liked the Schumann version, which is a really simple and elegant
> solution. I wasn't able to find out how it sounds though.

I liked it too. I also like Leopold's designs, for ease of 
manufacture and installation.
Ron N