In MMDigest 990901 D. L. Bullock wrote:

> This method of regulation to the piano will not cause a problem
> regulating the volume because the solenoid is stronger when the core
> is closer to its activated position.  The smaller travel will cause
> better pianissimos, louder fortissimos, and better repetition...
> A pneumatic is stronger when it is farthest from the activated
> position.  So we pneumo-heads have to adjust our thinking when
> working with solenoids.

As you read this, you have probably already read my solution to my
Pianomation problem.

Even though "power" is important in playing pianos, the most important
factor is impulse.  Impulse is what actually plays the piano more than
anything else.  I disagree with the solenoid having better repetition
with a small stroke.  Here is why.

Even though a solenoid is indeed within it's electromagnetic "range"
with a short stroke, you also restrict it's impulse that way.
Moreover, the solenoid's power is very limited.  In restricting it's
stroke, you restrict it's power; add to that the weight of the key and
the lost motion "bounce" between the capstan and sticker that often
occurs with short quick notes.  If you look carefully, you will find
the sticker "floating" above the capstan.  This is what causes
Pianomation to "slur" quick repeated notes more than anything else.
Anyone who has owned one of these units has no doubt noticed that these
do not have the response like a pneumatic player does.

I adjusted my Pianomation unit every which way.  If I limited the
stroke, it would solve the pushing the keys off it's center pin, but
then there was another problem: lack of a solid 'catch" during soft
playing.  The solenoid was so weak at that point, it would not push the
key up to the point that the backchecks would work.

So I finally came to this conclusion: for the Pianomation to make
serious music, some sort of compound leverage needed to be added to
take advantage of the solenoid's full stroke _and_ have the proper
travel on it's piano action at the same time.  To be efficient, the
burden on the solenoid had to be as light as possible.

In my view the method of installing a player under the keybed in
uprights is a bad idea anyway.  In that area on some old uprights you
will find less than 1/2" travel, even when the key dip on the front is
correct.  That is simply not enough distance to get enough impulse to
play solidly, especially from a small solenoid.

The old Krell company in the 'teens built an upright with the stack
under the keybed.  It had the same problems, even though it was
pneumatic.  It wasn't long after that that they made their uprights with
the stack up top...  Wonder why?

Another thing: cutting the keybed and whacking off the key supports and
relocating the back rail is risky in an upright.  That piano wasn't
designed to work that way.  The old guys knew exactly why the player in
an upright had to be located _above_ the keys.

In a grand piano, you have no choice but to mount it that way, but I
still think grands could benefit from installing compound linkage to
allow more travel on the solenoids.  Even some reproducing grands had
some sort of compound linkage.

In uprights, there is no reason that the solenoid should have to bear
the weight of the key, not with a 1-to-1 ratio.  That solenoid will
never have the power to play softly _and_ catch on the backcheck every
time.  There is no valid reason to "play" the key anyway unless it is a
console without stickers.  Just more weight to burden the solenoid and
slow it down.

Once I relocated the Pianomation above the keys in my upright -- giving
the solenoids enough leverage to do their job and taking the burden of
the keys off of them -- my piano was too loud at the normal setting.
The response is 100% better than it had ever been since I bought the
unit two years ago.  It will now compete with any pneumatic unit out
there.

Pianomation is a great product, I am not saying otherwise.  But if you
will apply some leverage using (fingers before it engages with the
piano action), and the designs that the old player builders used, and
apply it to this action, I guarantee it will be worth the extra effort.
Next grand installation I do, I intend to do that very thing.

Best regards

Andy Taylor

 [ Editor's note:
 [
 [ I invite opinions from others about impedance matching between force
 [ transducers (pneumatic and solenoid) and the piano action.  In my
 [ view both pneumatics and solenoids can be optimally designed for
 [ long stroke _or_ short stroke applications, but not _both_.  It's
 [ not surprising that a "one size fits all" player action doesn't
 [ work well in every installation, and I caution against drawing
 [ conclusions from only one situation.
 [
 [ Robbie