> It is easily possible to design a string termination system that keeps the > energy in the speaking portion of the string until it is transferred into > the soundboard system. For examples look at the typical upright design. > Simple and effective. Keeps the string angles reasonable and short. No noise > and no tricky work required on the V-bar except with the most sloppy plate > castings. Geometry wise this is a bit tricky to pull off on a grand plate, > but there are other ways of accomplishing the same thing. So maybe my little 1906 Everett with the cast V-bars and pressure bars - just like an upright - has some potential? Have you run across one of these before? Terry Farrell ----- Original Message ----- From: "Delwin D Fandrich" <pianobuilders@olynet.com> To: <pianotech@ptg.org> Sent: Tuesday, June 26, 2001 10:16 PM Subject: Re: Agraffe tuning easier or not? > > ----- Original Message ----- > From: "phillip l ford" <fordpiano@lycos.com> > To: <pianotech@ptg.org> > Sent: June 26, 2001 5:46 PM > Subject: Re: Agraffe tuning easier or not? > > > > ------------------ > > Why do you say that the Sohmer and Heintzman designs are taken to an > illogical extreme? I haven't heard a broad sampling of these pianos but of > the ones that I have heard I thought the top ends were pretty nice. I > attributed that partly to the connected capo. > > ------------------ > > Both were very difficult plates to cast and machine. Any improvement in > actual performance due to this feature is so small as to be virtually, if > not in fact, undetectable. While it is possible to measure some movement of > the capo d'astro bar in response to both the hammer impact against the > string and to the vibrating string, it is doubtful that the loss of audible > energy to this alone is either detectable by ear or measurable by machine. > > I have heard some Sohmer and Heintzman grands with this feature that had > quite nice treble sections and some that had quite poor treble sections. I'd > look elsewhere for the reasons. > > If you'd like to couple the capo d'astro bar to the pinblock panel, the > Baldwin system of individual termination pieces with a machine screw going > to either is a better solution. Even though the part itself is rather costly > it is probably still easier and more economical than either the Sohmer or > the Heintzman system. > > > > > ------------------ > > It seems that there is going to be some inevitable 'leakage' past the capo > bar or agraffe. So the string portion on the side of the capo opposite the > speaking length is going to be moving. You say that energy is being lost by > having a tuned aliquot design. Do you feel that less energy would be lost by > having a detuned aliquot design or by having this section damped out (felted > out) altogether? > > ------------------- > > No. You don't want it to get there at all. Once the energy is there, damping > it out just makes a bad situation worse. > > It is easily possible to design a string termination system that keeps the > energy in the speaking portion of the string until it is transferred into > the soundboard system. For examples look at the typical upright design. > Simple and effective. Keeps the string angles reasonable and short. No noise > and no tricky work required on the V-bar except with the most sloppy plate > castings. Geometry wise this is a bit tricky to pull off on a grand plate, > but there are other ways of accomplishing the same thing. > > > > > ------------------- > > Why is the Baldwin design inherently inefficient? > > ------------------- > > The string angles are too shallow and the duplex length is too long. (OK, > those with the back-bearing riser reversed are better.) Otherwise it's a > great system. > > -- Del >
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