* Fred Sturm (fssturm at unm.edu) wrote: > On Jan 20, 2011, at 12:31 PM, Don Mannino wrote: > > >This one is 7 grams. See photo. > > > Yes, but we were talking about the bridge agraffe, either Stuart's > or Phoenix system. Different animal. They could well weigh anywhere > from 5 to 12 grams, at a guess, with the cylinder that bears down on > the strings as the big variable (don't know if it is solid or > hollow). I've tuned a few Stuart pianos, including one of his first which has been in use in the Conservatorium in Newcastle (NSW, Australia) where he has his factory, and another in the PowerHouse Museum of Technology (Sydney). And I've been underneath the new one which is getting all the publicity at the moment. The agraffe has undergone continuous development. The current version is of some light strong brass-like material, and the three pins are these days made of titanium -- I think -- previously he has tried a ceramic pin. A couple of points missing in this thread: 1. The termination at the front is identical, it involves a similar agraffe attached to the plate, but upside down. So the wire passes under this agraffe and over the bridge agraffe. It is thought that the vibration is more elliptical than transverse with this arrangement compared to the typical bridge + steel bridge pin with the wire bent around the pin. 2. Wayne Stuart goes to a lot of trouble to ensure that the string is in a straight line from hitch-pin to the plate-agraffe, by setting the height of the wire at the hitch-pin, rather like the "accu-just" system. That part of the process is done without the middle pins which bends the wire down. The design of the agraffe allows for the middle pin to be pushed into place quite easily once the straight line has been established. 3. The soundboard is not part of an opposing spring system, so is under less stress than the typical soundboard. In fact probably under no stress at all, which may be a large part of the amazing sustain. I think the board is marginally thinner than usual, and in the current models Mr Stuart is using a web pattern in the ribbing. The ribs are much smaller in profile than usual. Tuning the Stuart is a dream. All the coincident partials you're hoping to hear are there, as obvious as you can hope for. There is less of that strange dance of the partials receding and reemerging and slowing down that you get on other pianos. The clarity is extraordinary, and wonderful for a tuner, but the same feature perhaps takes away from the random color that pianists expect.
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