Hello all, I have been trying to catch up on my reading lately,and came across an article in the Feb. Journal that brought together a discussion that took place here on pianotech during the previous month (I guess?) .I had not at that time subscribed to the list. In any event,the subject of the discussion was capo d' astro bar shape,composition, etc. and the "buzzs,zings,and other noises" that emanate from the front duplex on many makes of grand pianos and how those problems arise, with several ideas on how to deal with them. I was surprised that no one mentioned that a significant reason for these unwanted sounds is the lack of sufficient angle of the string as it passes under the capo and rises toward the upper string rest. We all know that if this angle is too severe,tuning and stability problems will result (witness that un-tunable monster,the Steinway upright) ,not to mention the high probability of string breakage and other gremlins.But, if that angle is too small,I have observed that the capo section of the string *will* "zing and jangle" Could it be that the speaking lengths vibrations are "leaking through", causing its capo section string partner to vibrate. Yes, a grooved capo will cause a buzz, and that buzz can often be eliminated by moving the string back and forth under the capo bar thereby,I believe, burnishing the bar a little, removing the little "hill" of iron that grew as the little "valley" was worn in by the string.(That metal has to go somewhere). One can also voice that noise down or out. That type of buzz is heard in the speaking length more so than in the capo section. I have a Steinway D at my school that had a terrible problem with these kinds of noises. No amount of voicing,different hammers,shaping of the capo bar,etc. had any effect on the problem. After numerous disappointments,I began reviewing all that I had done so far to effect a cure. I occured to me that when I did any shaping or filing of the capo bar I was actually changing the angle that exists between the capo and upper string rest. If that angle was too shallow to start with, then my work on the bar was exacerbating the condition. As an experiment,and since I could think of no easy way to add metal to the capo, I added individual pieces of formed sheet brass to each upper string rest. The thickness of the brass was .016"-.020". These were covered with felt and the piano re-strung. Result: NO BUZZES,ZINGS or Other noises. There are no tuning problems,either. By increasing that angle I also increased the length of the front duplex. Not much,I'll admit,but some. So it seems that either the increased length or the increased angle or a little of both served to eliminate the unwanted noises. I have applied this procedure to several pianos over the years, it always seems to work for me. Hope this hasn't been to long, and that my rusty writing skills have allowed my point to get across. Paul Dempsey Marshall University Huntington,WV. wippen@aol.com
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