Getting the high trebble right

[Stéphane Collin]

Hi John.

At the moment, there is 5 mm felt between the molding and the crown at
hammer 88.  On the older hammers, though, there was nearly nothing left.
Yet they sounded very well, musical and all.  That might very well be a
start point for experiment.  But if I reduce the felt layer by 3 mm , I will
have to re hang my hammers, not ?  If so, well that is life, as someone
recently told me.  I spent some time in checking the right angle condition
between hammer and strings at contact time, as you convinced me that this
condition is absolutely crucial, certainly in the treble. (I'm convinced,
certainly).
What is your favourite dope ?  I indeed am always deceived by the
acetone-key top mixture, as it brings some high partials at the cost of
colour shades dynamics (who disappear), and no more question of fine voicing
after.  But I always put the mixture from top.  I will certainly try at the
moulding next time.
I like your idea of letting the different hammers bounce on a hard surface.
Makes so much sense, as always.

Thanks for your valuable input.

Stéphane Collin.

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of John Delacour
Sent: vendredi 13 juin 2008 23:06
To: Pianotech List
Subject: Re: Getting the high trebble right

At 20:58 +0200 13/6/08, Stéphane Collin wrote:

>Old hammers were lighter than the new ones, but new ones (Renner Wurzen AA)

What thickness of felt have you between the strike point and the 
moulding wood?  Quite often Abel gives you too much, which means you 
get far too long a contact with the string.  You can either inject a 
hard-setting dope at the point of the moulding or reshape the top of 
the hammer.  Applying dope from the top downwards will not achieve 
the effect you want.  Let the old hammer and the new bounce on a hard 
heavy surface and see how differently they behave.

JD