[CAUT] Thank you for Stability advice

PAULREVENKOJONES at aol.com PAULREVENKOJONES at aol.com
Tue Feb 9 21:00:45 MST 2010



In a message dated 2/9/2010 5:48:45 P.M. Central Standard Time,  
A440A at aol.com writes:

Greetings, 
I don't tap pins or strings,  usually. 
Nor do I, nor have ever advocated it. But...

What I have found effective is a very light press on the  string, directly 
behind the distal bridge pin and then in front of the  proximal bridge pin, 
with the tip of my tuning hammer.  This is against  the direction of the 
wire's curve as it comes off the bridge pin.  This  is not downward, but 
rather, into the pin.  It straightens the wire's  meniscus (the slight curvature 
in the wire).  Even old pianos often   go flat and improve when this is done. 
 Almost invariably, there is  anywhere from a .5 to 1.5 cent drop,(newer 
strings drop more than older  ones).
I do exactly the same thing but with a piece of maple dowel with a piece of 
 leather around the tip. No steel on steel. There is always a pitch drop,  
although I've not measured it as accurately as you. 


Not only do I notice an  improvement in stability of tone,(easily seen in 
the SAT display), but it is  amazing how many false beats disappear when I do 
 this.
I agree with everything you say here except the use of the word  
"disappear". Perhaps "recede" and it is not permanent (for many of the reasons  that 
David and Ron have already discussed--pace Ron). It has been my  many 
experiences of return to the same piano only to find the false/real beats  having 
returned (precessed? if it was a recession at the outset). 
 

I surmise that there is a better tone coming out of  a string when the 
restorative force of the curve is  removed. 
Interesting and probable, but undemonstrated except by way of the recent  
experimentation by Ellis and others on false/real beats as a result of string 
 curvature. 

The same thing happens when I straighten out the downward  curve at the 
capo or agraffe.  This curve will never completely resolve  itself by the 
simple tension, since the closer it gets to straight, the less  effect the 
tension has to straighten it.  To "train" carbon steel, one  has to exceed its 
deformation limit.  With 170 Lbs of tension on the  wire, it takes very little 
force to actually make the string leave the pin  with a curve in it.
Another problem is the internal shape of the agraffe which is not radial  
but flattened in the center between the countersinks. The wire never entirely 
 seats itself on the shape, leaving two points of contact inside the 
agraffe.  I've experienced both more and less transient noise from pulling the 
string up  at the agraffe. I've never experienced the same issue at the capo, 
particularly  after dressing it properly. There is, of course, a solution to 
the agraffe, but  that's another hobby horse.

In this case, the outer circumferance of the  curve as it goes around the 
pin must stretch a little more than it would by  simply being pulled tight 
around the pin.  
I do  this as I tune.  It is quick, simple, requires no tools other than 
the  one in hand, and makes tuning easier, tone better.  
regards,  

Ed Foote  RPT
http://www.uk-piano.org/edfoote/index.html
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