contraversial basic reguLating

[John Delacour]

At 16:48 -0500 15/2/08, KeyKat88 at aol.com wrote:

>Maybe my understanding of Aftertouch is not right. I understand it 
>to be the feeling of resistance (like a shelf thatÊ's about to 
>fall)Êthat the player feels just when the jack is about to flip 
>out..Is that right?

That might be a symptom in a grand but there is no such thing in an 
upright, which is what you're asking about, because there is no 
resistance to the jack escaping from under the notch.

What you are aiming for, whether in a grand or an upright is a touch 
depth that will allow the jack to clear the roller as the hammer 
falls into check (on a grand, and the jack to be just clear of the 
notch leather when the hammer falls into check on an upright.  Any 
deeper touch will result in wasted movement, slow repetition and (in 
extreme cases on a grand) snap the jack as it is forced into the slap 
cushion.

If the touch is deeper than it needs to be on a grand, you will need 
to push back the checks and besides, you will get a wrong reading for 
the drop, particularly on the Erard/Herz action.  On an upright too 
you will need to pull out the checks to compensate for the excessive 
touch depth.

There is no fixed value for touch depth -- it depends on the design 
of the piano and on the true value you set for the blow, by which I 
mean the distance the hammer rests from the strings when sitting on 
the capstan.  If a player asks for more touch depth then you have to 
increase the blow and for a shallower touch depth reduce the blow and 
add or remove washers to suit.

"Lost motion" in an upright is regulated by fine adjustments to the 
hammer-rest so that the notch is just clear of the top of the jack 
when the system is at rest.

If the butt cushions are in good condition, there will be absolutely 
no variation in the ratio of blow to touch-depth through the scale 
and no need for some of the suggested methods I have read here.  It 
is most important that the butt cushions be in good condition and of 
equal thickness throughout the scale, because a worn butt cushion 
will change the leverage of the action, giving more movement of the 
hammer for a given touch depth.  Wear in other parts, such as the 
lever heel, the set-off button are not important at all and will not 
prevent proper regulation of the action.  If the butt cushions are 
good, the set-off is correct and the blow is correct, it follows that 
only one value for touch depth is possible and this will be even 
throughout the piano.  When the piano is regulated and checking 
evenly throughout, then the checks will be in a perfect line when 
they are at rest.  If they are not, then something else is wrong -- 
either the blow or the touch depth.

Set-off is not a variable quantity.  You determine the set-off that 
the piano will handle (anything from 1mm to 3mm if you have no 
celeste) and regulate every note the same.

JD