<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <META content="MSHTML 6.00.2800.1458" name=GENERATOR></HEAD> <BODY> <DIV><SPAN class=510363120-16082004><FONT face=Arial color=#0000ff = size=2>Hello all !</FONT></SPAN></DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial color=#0000ff = size=2></FONT></SPAN> </DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial color=#0000ff = size=2>I also have heard different statements:  backchecks being 2 mm lower than = the hammer tail et letoff , or at drop.</FONT></SPAN></DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial color=#0000ff = size=2>STEINWAY : backchecks  height is 2mm under the tail of the = hammer (shank at horizontal, meaning more or less letoff) THEN the backchecks wire is angled to provide the 72 ° angle, and consequently = the height of the backchecks turn to be more 2mm after drop than letoff. </FONT></SPAN></DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial color=#0000ff = size=2></FONT></SPAN> </DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial color=#0000ff = size=2>Why does it add some power or opening to tone , I have 2 = ideas.</FONT></SPAN></DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial color=#0000ff = size=2>The backchecks being lower the wire is more rigid, so the bump of the hammer = coming in check is stronger.</FONT></SPAN></DIV> <BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px"> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2>This bump arise while or slightly after the hammer have hit the strings, so = it is obvious that if that knocking is happening longer because of lower = backchecks or also lower checking, the bum of the key is prorogated with the bump = of the tails coming in check. I'd suppose that a longer bump gives more = energy to the tone (we are yet in a moment where the tone is not = stable may be even the first wave train is only beginning to move toward the bridge, = nowadays, I suspect we are still in the "energising" moment of = the acoustic system)</FONT></SPAN></DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2></FONT></SPAN> </DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2>The hardness and resiliency of the front punching is more acting as a = mechanical goodie in my view, indeed there is a bum noise with the key bottoming, = but see more efficiency in the system acting in a cycle of compression/release = and then the added firmness is acting like the see saw (explication : TM Andre)</FONT></SPAN></DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2>A harder bottom propulse faster the system.</FONT></SPAN></DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2></FONT></SPAN> </DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2>Landing of the hammer tail does not say much to me, = eventually a shorter wire will provide a harder landing than a longer wire, but in = any case the good checking is when the hammer tail will rub the backchecks = (with a nice scratchy noise) if the hammer is in drop and pushed down slightly, and = IS NOT rubbing the backchecks when rising and being restricted (shank flexed slightly) with a finger.</FONT></SPAN></DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2></FONT></SPAN> </DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2>If an action get too noisy with firmer punching, possibly the key bed is = in soft wood too resonant, but also the travel/ letoff/drop and = backchecks /dip  is not optimum, and the key bottoms too early before the hammer = produce a tone - that is why synchrony between drop and letoff is unavoidable, = that is the only way to compress the system with friction, limiting any bump = and landing noises.</FONT></SPAN></DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2></FONT></SPAN> </DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2>Was it ok friends ?</FONT></SPAN></DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2></FONT></SPAN> </DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2>Best regards.</FONT></SPAN></DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2>.</FONT></SPAN></DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2>Isaac</FONT></SPAN></DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2>Best regards.</FONT></SPAN></DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2></FONT></SPAN> </DIV> <DIV><SPAN class=510363120-16082004><FONT face=Arial = color=#0000ff size=2></FONT></SPAN> </DIV></BLOCKQUOTE> <DIV class=OutlookMessageHeader dir=ltr align=left><FONT = face=Tahoma size=2>-----Message d'origine-----<BR><B>De :</B> = pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org]<B>De la part de</B> antares<BR><B>Envoyé :</B> lundi 16 août 2004 = 21:37<BR><B>À :</B> Pianotech<BR><B>Objet :</B> back check, a magical mystery tour.<BR><BR></DIV></FONT>Hello List, Avery, Stephane and = Richard,<BR><BR>I have written about this mystery issue before a long time ago. I personally = have no explanation for it.<BR>I just learned this from a very gifted Japanese = teacher. he introduced me to "the one and only right position" of a back check = versus hammer tail.<BR>According to him (Tsuji-san), there should be a space of = 2 mm <B>after drop</B> between hammer tail and back check.<BR>Indeed that is = true, and it is a mighty weapon.<BR>Throughout the years, there have been many = miracles described on this list to improve tone and action.<BR>If we = delve into all what has been said, we must come to the conclusion that, to achieve = the very best in regard to the way an action performs and to get the ultimate outcome...the tone, our profession is extremely complex.<BR>The mystery = of the back check has not been solved yet. I have as of yet not heard an = explanation that totally convinces me. Nor was Tsuji-san able to explain it to = me.<BR><BR>A <B>very</B> powerful regulation is one thing, to make a <B>fantastic</B> = tone another.<BR>Among the weapons we are able to employ are : <BR>1. Our = experience, talent, knowledge and understanding first of all<BR>2. The use of high = quality materials like : the best felt and the best front punching (indeed = heavily underestimated)<BR>3. A thorough understanding of the use of = anti-friction material, and what it really means<BR>4. The ability to make a superb = concert tuning<BR>5. The ability to bring a voicing to a high = standard.<BR><BR>As described above, the back check height belongs to this list. It is a = very handy help in the voicing process.<BR>We start this process with the usual = list, like anti-friction treatment, regulation, tuning and voicing, but we can = improve the final outcome with the help of this back check phenomenon.<BR>To give = you a clear example :<BR>A long time ago I had to prepare a number of = instruments for customers in the showroom of Yamaha in the Netherlands.<BR>After a few = rounds, one C5 grand was their favorite, but they explained to me that still <I>something</I> was missing.... it was <I>just not </I>powerful = enough.<BR>My piano instinct told me to do the one and last thing : I told them to = have another cup of coffee (yes Huber Liverman!) and I also told them that I = knew exactly what they meant.<BR>This was partly true, but also bluff on my = side, but under the circumstances, my professional life was on the block.<BR>I got = out my Japanese tool to change the height of the back checks and I started = twisting and turning the back checks to the desired height.<BR>On the way I broke one = of the back checks but was so extremely lucky to be able to replace it = immediately and without their seeing any of it (they were busy slurping their adrenalin).<BR><BR>After 10 minutes, I wiped the sweat from my brows and = joined them for my round of the brown stuff, and I told them that I thought I = had successfully solved their complaint.<BR><BR>They went back and played = the C5, <B>and bought it immediately!!<BR><BR></B>Thanks to the generous lesson = of Tsuji-san.<BR><BR><BR>André Oorebeek<BR><BR><BR><BR>On 16-aug-04, at = 8:27, Richard Brekne wrote:<BR><BR> <BLOCKQUOTE>Hi Avery<BR><BR>In the case of the grand at the University, = they were higher then what turned out to be best for the sound. I am not = sure whether they can be too low in this regard. Andre is following the = whole thread so I am sure he can answer better.<BR><BR>btw... I've heard the = standard set both 2mm above and 2mm below the hammer tail at let-off = through the years. Quite a few times both ways actually. It would be nice to = hear what the consensus is here.<BR><BR>Cheers<BR>RicB<BR><BR>Avery Todd = wrote:<BR><BR> <BLOCKQUOTE>Ric,<BR><BR>Just curious. Is Andre referring to the = backchecks being higher than normal<BR>(2 mm below the hammer tail at let-off), = or lower?<BR><BR>Avery<BR><BR> <BLOCKQUOTE>This brings me to another one of Andre's suggestions... = that about the height of the backcheck having an impact on tone. Now = this one is just plain weird sounding... I'll be the first to admit it... = but there it was. When Andre was up here a couple years back he demonstrated = it to 5 of us, and no one could avoid admiting that he'd changed the = tone... the openess of the tone on the notes he'd adjusted. I asked the famous = Japanese pianotechs Mr. Ono and Mr. Takahara about this too whilst = I was in Japan this summer, and they both immediatly responded along the = lines... "but of course-- didnt you know that ???"... tho to this = day I have yet to find a satisfactory explaination for why the height of = the backcheck can influence the openess of the tone of the = piano.<BR></BLOCKQUOTE><BR><BR>__________________________________________= _____<BR>pianotech list info: = https://www.moypiano.com/resources/#archives<BR><BR></BLOCKQUOTE><BR>___= ____________________________________________<BR>pianotech list info: https://www.moypiano.com/resources/#archives<BR><BR><BR></BLOCKQUOTE>fri= endly greetings <BR>from<BR>André Oorebeek<BR><BR>Amsterdam -<BR>The Netherlands<BR><BR>www.concertpianoservice.nl<BR>www.grandpiano.nl<BR><BR= >"where music is, no harm can be"<BR></BODY></HTML>