---------------------- multipart/alternative attachment Hi there Ron... Thanks for the lengthy reply of last week. Jiminees... where to start. I guess I will plunge right in. About all this with the front termination, specifically the capo bar or the equivilant in uprights. I am glad to hear that you share some of my thoughts regarding the profile question. Not that I am an expert in these matters, yet I have followed Ed McMorrows proceedure for several years now with excellant results. Let me digress a bit According to my understanding of things there are two basic configurations for the front termination (capo or similiar) You can either go for hard, round, and wide... or soft, thin, and sharp. The former is prevalant today and is a natural result of the basic history of the capo bar. A short synopsis... again my understanding of things..... Historically the profile itself had never been considered important enough to warrant any detailed and precise shaping at the factory. Looking at older top quality instruments this seems likely if not out and out obvious. At some point in history it is noticed that there is considerable wear and tear at the surface of the capo, and lots of noise comes from it. Naturally enough the impulse is to harden the surface... which lead to a lot of string breakeage... so this in turn naturally enough led to widening and rounding the termination profile (load dispersion argument). Very few seem to have considered that sharpening the capo and leaving it unhardened... or at least not hardening beyond absolutely neccessary... could be a better or just as good a solution. Tho you do see this approach in different places.. the Jacob Knudsens for example employ a top (front) termination that cant possibly be more then 0.3mm wide and angles off from this barely rounded at the edges knife edge at approximately 15 degrees on either side forming a definant "V". The idea seems to be that given the hardness of the wire, there exists some sort of a "hardness co-efficient" for the capo bar dependant on its profile. A hard termination requires a wider rounder profile to avoid string breakage. A sharp termination requires a softer termination for the same purpose. But what else comes into play ?? The load dispersion argument points to the improved wear and tear characteristics of the wide and hard capo, yet there is no argument for the sharp and soft in this regard. Experience and observations however point to the very clear possibility that a softer termination that is very thin and sharp can stand up very well indeed, without any string breakage. So what else then ???? Inharmonicity considerations...... and scale tensions... There is some hard science that points to a difference in inharmonicity between the two configurations. Ed in his book states it outright tho I have been unable to find his source for this declaration. Coltman in the mid 30's did some looking into this but it was done mostly in regard to the bridge termination and his results point more in the direction of negligeable differences. My own measurements with RCT (granted a weak tool for certainty in this regard) concur with Eds contention tho that the fat and round termination results in higher inharmonicity curves then the thin and sharp. You have more of a hinge effect in the latter then in the former. As far as wear and tear on the capo itself then.... both configurations will groove eventually... I personally cannot see for the life of me that one type will groove any more or less then the other. (exception being the soft and fat halfrounds found on Schimmel uprights... they groove very quickly) The question is more which is more troublesome soundwise then. My experience tells me that in this regard the wide, round, and hard causes much more noise when grooved then the sharp and thin. I have always suspected that there is something about the way the string vibrates on the termination point itself that is partially to blame. Thinking again in terms of the hinge, it is not hard to imagine causes and effects that would explain this to some degree. Secondly a roundish temination is by definition not so precise... at what radius does one completely avoid any possibility of string buzz due to the strings amplitude at the termination comming into contact with part of the termination only half the time as it were. Such buzzes would be characterized by the fact that they would disapear as the strings energy dissapates. I find plenty of those kinds of buzzes around on pianos with this kind of termination.... and have yet to find that kind of thing on the thin and soft. In fact I rarely find sting buzz that I can relate to the termination at all when the termination is thin as soft. This prerequisites a very presise and very thin profile mind you. No more then 0,5 mm wide and very much "V" formed... not rounded Ok... so you have my basic picture of things and some of my experience to go with it. You mention that you are going to try out a thiner profile soon. It will be interesting to see what kind of string breakage you end up with if you harden as much as you are used to. So keep me informed. Did you ever get ahold of Ed McMorrows book "The Educated Piano" ? If so I would be interested in hearing what you have to say about his comments relating to the plate, and this termination. Otherwise I concur completely with your comments about the front duplex (thats called the real duplex by many over here btw) It is best when "detuned" The idea that a tuned duplex steals to much of the energy from a sounding lenght.... especially when the termination is conducive to this energy loss (another argument for a thin, sharp, and then neccesarilly soft termination) is very appealing on the surface of it. Again,.... these are the understandings and speculations of an unschooled mind. I read a lot... and keep my eyes open as best I can... and try to be objective. But I am no scientist...grin... On the side.... whats this about the Stuart piano and bridge agraffes I hear.... bridge agraffes... that concept has always intrigued me.... Hope this finds you well. m'Best to you -- Richard Brekne RPT, N.P.T.F. Bergen, Norway mailto:Richard.Brekne@grieg.uib.no ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/91/82/4d/0b/attachment.htm ---------------------- multipart/alternative attachment--
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