[CAUT] Black on Black... (Jack alignment)

[Douglas Wood]

I was urged, in The Basement, to keep the jack aligned with the back  
of the knuckle core so there would be no cheating on the loundest,  
hardest, fastest repetition. As it's been pointed out, a failure here  
is much worse than having the action feel just slightly heavier.

Their contention was that overall the repetition was actually better  
with the jack aligned with the back of the core.

It's been my experience that there are other issues at work with a  
"constitutionally slow" instrument.

Doug Wood
University of Washington


On Aug 10, 2007, at 5:08 PM, Fred Sturm wrote:

> On 8/9/07 6:31 PM, "Tim Coates" <tcoates1 at sio.midco.net> wrote:
>
>> Fred,
>>
>> I would be interested in knowing if you experience the same issues  
>> I think
>> Chris Soliday eluded to:  the jack back versus the jack forward  
>> affects speed.
>> I agree that .5mm is a great deal of discrepancy and should not be  
>> there.  I
>> deal with a number of Van Cliburn finalists and students from TCU  
>> (yes here in
>> the Dakotas).  One of their obsessions is speed of repetition.   I  
>> see how
>> what you are doing can be used with my methods.
>>
>> I am always trying to tweak the performance instruments in my care  
>> and I find
>> jacks to be critical to the condition of the piano.
>>
>> Thanks,
>>
>> Tim Coates
> Hi Tim,
>     I don't think jack alignment (within normal parameters) affects
> repetition. It doesn't matter whether it gets back in contact with  
> the stop
> (ie, its regulation button felt contacts that metal upright) or not  
> during
> that fast repetition action, just that it gets under enough at the  
> right
> moment to stay there and not cheat out during the next stroke. What  
> matters,
> I think, is the stop felt at the end of the rep window, and the  
> amount of
> aftertouch. Felt being closer, and aftertouch less, means faster  
> repetition.
>     Looking at those high speed videos, what strikes me is the  
> bouncing of
> the jack against the knuckle, often several times and long bounces  
> during
> very fast repetition. Repetition will fail if the jack happens to  
> be in one
> of its bounces at the wrong time. So I figure the less bouncing,  
> the better
> the repetition. You'll get less bouncing if your stop felt is  
> closer in, and
> if you aren't pushing the jack as far away from the knuckle with  
> the key.
> You push the jack farther with the key if you have more aftertouch.
>     These aren't the only factors. Obviously rep spring strength,  
> friction,
> etc come into play. But my sense is that aligning your jacks  
> outward won't
> improve repetition speed. It will make the feel of letoff smoother  
> and less
> noticeable, which will affect the touch, and there may well be many  
> fine
> pianists who prefer that feel.
> Regards,
> Fred Sturm
> University of New Mexico
>
>