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MMD > Archives > December 2001 > 2001.12.08 > 04Prev  Next


Ampico "A" Expression Problems
By Craig Brougher

Nathan Bello asked about a strange problem with an Ampico player.
It plays full force when the automatic switch is turned off and weakly
when it's on.  With no more information than that, I'd say that's
clearly an error in tubing it up.  But you didn't make it certain that
the bass plays exactly like the treble at the same time.

Anyway, there are 3 things that will raise the power in an Ampico A:
1) the crescendos, 2) the 3 expressions, 3) finger buttons.
There is nothing else except the amplifier which works dependently
upon the expression.

So if your piano is fully restored and it worked when it left the shop,
then I'd say that some of the tubing got pulled off in transit and
replaced wrong.  It's easy to tell.

First, you put the piano in play with a regular 88-note roll on
(no expression holes to worry about).  Get it going, switch the piano
over to "automatic off", put the tempo on 0, pull the power plug and
hop under the piano (if it's a grand) and remove the belly cloth.

Once you are situated and have some light under the piano, plug in
the motor again and watch the crescendo bellows.  If one or both close
down, that's where at least one problem is.  Trace the 1B and 1T tubes
and you will find that problem.  They should go through the automatic
cutout strip, and straight to the trackerbar.

On the other hand, let's say the crescendos just sit there, balanced
on the pallet.  In that case, put your hand up above the expression
units and see if you can press down any of the little primary buttons
-- if they are actuated.  I doubt that, because you have turned off the
player with the roll on, and then turned the player back on.

If "no" to both possibilities, then reroll the roll, and start from
scratch and begin the roll as you do normally, then hop down and check
it out in the same way.  If "yes" to one or both possibilities, then
you are activating the expressions when you put the roll on, before
it has a chance to cover the trackerbar and play.  That also means the
cutout strip is on when it's supposed to be off, and off when it's
supposed to be on.

Let's say that both bass and treble are doing exactly the same thing.
Check to see that the Ampico automatic (air) switch that says "on-off"
is giving you air when it says off and is closed tight when it says on.
So locate that tube in the bass side of the drawer (if a grand) and
make sure the automatic cut-out strip is truly open, allowing airflow
through it when the switch says Ampico On.

If the automatic cut-out strip is "on" for 88-note rolls and "off" for
Ampico rolls, then you would have what you describe most of the time,
because as the roll's leader passes the trackerbar with the repeat
switch on, the expressions might come on and stay on throughout the
roll.

The other idea I have is that you have a mess -- a bunch of errors.
For instance, a cut-out strip whose expression tubes have been switched
from the outputs to the inputs.  Easy to do.  One is above the other,
about an inch apart.  And there are multiple ways to switch the tubing
around.

But keep in mind the basics.  The three ways to increase stack
pressure.  Don't assume anything.  Just remember there are 6 tubes
in the bass, and 6 tubes in the treble that can do this, plus the two
finger-button tubes (which would not enter into your scenario as you
described it).

If you wish to eliminate the Ampico on-off air switch circuit, then use
nipples to connect together the 11 or so tubes that normally go through
the cut-out strip and play an Ampico roll.  If that works fine, then
your problem is in that (Automatic) circuit.

Craig Brougher


(Message sent Sat 8 Dec 2001, 16:07:52 GMT, from time zone GMT-0800.)

Key Words in Subject:  Ampico, Expression, Problems

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