---------------------- multipart/alternative attachment Greeting CAUTians, I recently subscribed to the CAUT list. For those of you who don't know me, we recently commenced manufacturing a 225 cm grand piano in Sydney after fifteen years of rebuilding. I started fiddling with pianos in 1975. The 225 piano we build can be viewed at; http://www.overspianos.com.au/OS003bk.jpeg Fred and Richard, Richard wrote; >Hmm.... well ok... termination issue it is... but a choice of a very >hard termination >neccessitates a choice of a round /wide termination... or string >breakage becomes an >issue. What about the option of adjusting the string deflection angles Richard? I've sent this info' to you on a previous occasion, and our exhibition piano at Reno had small radius hardened bars with detuned duplex lengths, set to an angle of under-fifteen-degrees. Did you listen to top end of this piano? While some will claim that excessive energy gets over onto the duplex if the angle is too low, if the length is not too long and it is properly detuned, the lower deflection small radius hard detuned bars will work extremely well. >. . One says V-pro results in a very hard metal, what little info I was >able to talk out of casting people seemed to hint in the same >direction, but then >others say this is only the skin, and still others say its actually >less hard then >green or sand cast plates. Regardless of what folks claim, our tests have shown that V plates are softer - at least for Kawai, Samick and Yamaha. This is what one would expect since V plates have a longer freeze time. The big advantage of V plates is that the longer freeze time results in plates with less distortion and internal stresses. These plates can be 'stuck' into a piano (which is usually how they are installed) without any need for de-stressing. >Same kinda argument from the experts goes on about internal damping >and plate ring, and >about the significance of a tighter more consitant resultant iron. >And the same kinda >argument goes about the inherent lubricity present and determined by >the amount of free >carbon in the form of graphites... > > >> And I can't see that the metallurgic differences between v pro and >>cast iron would >> affect acoustical inertness. The softer V plate should exhibit higher hysteresis loss. Further, a soft bar will grab the string on the edges of the groove, making rendering more difficult. Hardened bar pianos will render in six years time like they were recently strung. >. . I can say that when the V-pro plate first appeared >it was accompanied by horrible amounts of weird plate ring and plate >participation in >the sound. . . as they still do. Presumably to satisfy the requirements of the hearing damaged. I have noticed that folks with damaged hearing don't generally like 'clean toned' pianos. They seem to prefer instruments which are full of nasty string noises. >to enhance the highest partials... something he said was new at the time, >and much better then what anyone else had thought of. String noise is a very old piano making 'skill', with a long standing tradition. >I can also say that V-pro plate pianos are consistantly described by >piano techs as >having a slightly metallic sound.... not that this is neccesarilly a >negative... but >you hear this time and time again.. Yes well, with capo and duplex bars which are softer and therefore prone to being cut by the wire during string rendering, this is just what I would one would expect from an unhardened V plate. > >> In which case, as a choice of materials issue, it would boil down to >> hardness of termination. And v pro seems quite good from that point of > > view, at least in my limited experience. Not in mine, unless the bars have been heat treated. But they harden up just fine. We do it to every piano we build. >Grin.... no more then any of the rest of us I think. As Roger says >tho... When Yamaha >wants to make the absolute best they can... for some reason they >choose not to use the >V-pro plate, and for some reason they have stopped using tuning pin >bushings. Sure >would be nice if they put some hard data on the table for us all to read. Yamaha harden the capo bar (although the profile of the capo is generally quite ordinary), but leave the duplex bars soft. They also attempt to set the duplex lengths to a fraction of the speaking length as do Steinway. But the pianos built in both camps are still full of string noise. They've even developed a knack for building string noise into their agraffes. Cut an agraffe in half through the string hole and you'll see why. Lousy string holes profiles equal a noisy piano. Ron O -- Overs Pianos Sydney Australia ________________________ Web site: http://www.overspianos.com.au Email: mailto:ron@overspianos.com.au ________________________ ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/caut.php/attachments/9d/42/40/cd/attachment.htm ---------------------- multipart/alternative attachment--
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