---------------------- multipart/alternative attachment On 13-jun-05, at 18:58, Mark Schecter wrote: > Hello to all, I've only recently started reading this list, though=20 > I've known some of you for years. > > I would like to ask you to explain something to me. I have not read=20 > anything previously about these punchings, and so I'm coming at this=20= > with no previously-formed attitude. > > Jon Page wrote: >> I have been struggling with a rebuilt A which has been lackluster at=20= >> best >> and a textbook example of the killer octave+. >> Much to my relief, as I was installing these punchings I could = discern >> an improvement in the tone, it became more focused; more noticeably >> in the problem areas. (I know that I'm not going crazy because >> I've already crossed that threshold). Of course it didn't eliminate=20= >> the >> problems but certainly made them less bad, tolerable, imperceptible >> to some. At least now they don't jump out at you and do that little >> Nah-Nah-You-Can't-Touch-Me dance. > > I wish you, Jon, or Andre' or anyone here would explain to me _exactly=20= > how_ a punching under a key, which is not touched by the key until=20 > after let-off, can affect the velocity, trajectory, or any other=20 > characteristic of the hammer's flight (if there is any other) so as to=20= > have any influence whatsoever on the tone? Thank you for enlightening=20= > me. > > Mark Schecter > Oakland, CA > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives > > Hello Mark, I wrote an article for "the Journal" about this front punching. I also wrote many emails to the pianotech list. Here is one of my explanations : quote : Look at the key as if it were a sea saw with two little children on it. Normally speaking, when the sea saw comes down, it bumps into the=20 ground a bit, but, in order to prevent the children from getting hurt,=20= a rubber tyre is put on the ground on both ends to soften the shock. Nevertheless, when it goes a little rough, the child on the high end of=20= the sea saw has to hold the handle tightly, so that it will not fly off=20= when the sea saw hits the ground a little hard. Now we take away the rubber tires... The sea saw will really bang hard into the firm underground, and the=20 bigger shock, caused by it, is transferred immediately to the high end=20= of the sea saw. The child sitting on the high end may get airborne, handle or no handle. This transfer of energy is easy to understand and it proves how the=20 shock of a key hitting firmer 'ground' causes a more 'defined' touch,=20 and a louder, and sometimes clearer, tone. The new Wurzen punching feels more firm than most other punching, but=20 it is not too firm. When we compare it with another punching (for instance under the next=20 key), we notice immediately that the softer punching feels more spongy=20= and that after touch is less precise. The firmer Wurzen punching feels a little more firm, makes it possible=20= to regulate a very precise after touch, and hence causes a stronger=20 transfer of energy because of the more efficient regulation. On top of that, the extra firmness also causes a stronger reaction=20 straight to the hammer and we can instantly hear the difference between=20= the key with the softer punching. Sometimes it even seems a little=20 dull, and most pianists get very excited and immediately want the new=20= stuff (; >)) I have showed and explained this phenomenon to many people here, and I=20= always let them memorize touch and sound first, before inserting a=20 Wurzen sample under the very same key. I then let them try it out for themselves, so that I am not able to=20 suggest anything to them. In all these cases, the reaction was one of disbelieve and sometimes=20 great surprise, and I always urge them to repeat the procedure over and=20= over again so that they are absolutely convinced that it is not a hoax. So again, if any of you can not tell the difference, it maybe due to : A badly regulated instrument : the malfunctioning action makes it=20 impossible to distinguish any difference. A badly voiced instrument : the too soft or too hard hammers make it=20 impossible to distinguish any difference. A front punching which is just as firm as the Wurzen replacement. Your maybe lost your finest sense of touch and maybe also your finest=20 sense of hearing. unquote btw, here is another quote by Mr Stephen Birkett : quote : Also, instead of trying to observe differences in tone, I was simply=20 looking for a mechanical mechanism that would ALLOW the properties of=20 the punching to directly influence the tone, as well as demonstrating=20 that the key actually does behave very differently on impact with the=20 two kinds of punching. On the second point I will put a couple of video=20= clips on my website to illustrate, showing the key impact with standard=20= green woven and Wurzen white punching (I'll pass on the links when I've=20= got the videos into a manageable size for web-viewing). These don't=20 prove anything, of course, other than showing the felt properties of=20 the Wurzen punchings prevent the sloppiness seen in the decelerating=20 key with the green punching. In other words, the two types of punchings=20= cause a clearly different impact response from the key. Now, on the first point, a static viewpoint (as derived from=20 knowledge of standard regulation procedure and configuration) suggests=20= there is a clear association between aftertouch and the front punching=20= compression phase. However, dynamically (at least in the action=20 configuration I tested) this is far from a clear, or even fixed,=20 relationship. In fact, the simultaneity of statically adjusted events=20 can, and does, change quite dramatically under dynamic conditions. This=20= is really the most important point that leads astray when trying to=20 make arguments for or against a particular explanation of the behaviour=20= of a piano action. For example, in this case, the non-rigidity of the=20 action mechanism allows it to take on a configuration where the key=20 bottom has touched the top of the punching, while the jack is still=20 well under the knuckle, and has barely reached the letoff button.=20 Consequently, a direct mechanical link exists (for about 2.5ms) during=20= the escapement phase, i.e. PRIOR to any string contact, between the=20 pianist's arm, finger, key front, compressing front punching, and=20 through the key and action assembly all the way to the hammer. This is=20= what I meant by demonstrating a mechanism whereby the properties of the=20= front punching can directly influence the behaviour of the hammer=20 before it strikes the string. This doesn't prove an effect on tone,=20 just that it is clearly mechanically possible for tone to be influenced=20= in a significant way by changing the properties of the punchings,=20 consistent with the observations of Andre and others who've tried the=20 Wurzen punchings. Moreover, this explanation would suggest the effect=20 should occur under forte playing, and only with a very well regulated=20 action, consistent with Andre's frequently repeated observations from=20 his experience using the punchings in pianos. Stephen --=20 Dr Stephen Birkett, Associate Professor Department of Systems Design Engineering University of Waterloo, Waterloo ON Canada N2L 3G1 Director, Waterloo Piano Systems Group Associate Member, Piano Technician's Guild unquote Hope this helps. friendly greetings from Andr=E9 Oorebeek www.concertpianoservice.nl "Where music is no harm can be" ---------------------- multipart/alternative attachment A non-text attachment was scrubbed... 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