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MMD > Archives > August 1997 > 1997.08.08 > 09Prev  Next


Adjusting the Apollo Art-Echo
By Craig Brougher

Darrell Clarke was wondering about a test roll for his Apollo Art-Echo.
You may be happy to know that you don't need one.  It adjusts like an
Ampico (kind of), so with a GOOD gauge (not a Marshalltown) and lots of
patience, you will be able to get it right.

I restored one of the pianos years ago, and recall that the pump is
set to 33" after you have screwed down all the intensity screws first.
You have to begin that way, because otherwise, they interact.  The
intensities are not fixed ratios in this piano.  They are all separately
adjustable.

The first or zero intensity (whatever they called it) begins with the
metering pin position, but is affected by the regulator spring and the
pianissimo screw.  The pianissimo screw works in reverse of the other
intensities.  So by setting the zero intensity (we'll call it) between
1/2 and 1" lower than you want it to be, you can then start unscrewing
your pianissimo screw (for that side of the stack) outward until the
zero reaches the desired (say, 5.5") vacuum pressure.

To find the correct sub-intensity, you will play a note test roll and
test each note for the right loudness (there will be variances, and here
is where good rebuilders are separated out from the rest).  If you are
patient and work hard, you will be able to get them all playing at a
sub-intensity reliably.  Otherwise, you cheat a little and say, "that's
good enough." But at the first regulation, you might just rough them in
and go on to see what you run into down the line.

Adjust the pressure marginally at first to find the weak and strong
notes.  Mark them for future regulation.  Be SURE your test roll has
full-sized holes, like an Ampico roll, or you'll never get it regulated.

The metering pins are to be sitting at the position where the taper is
right at the edge of the hole when you are at the zero intensity You
adjust the regulator spring for zero, and then open the pianissimo screw
to touch it up.  In other words, without pianissimo, you have
sub-intensity.

To adjust the intensity steps, you will remove the respective tube going
to that expression valve to be adjusted.  The cancel tubes are still
removed.  The first intensity is adjusted to increase zero by 1".  The
second intensity raises zero by 2.5".  The third intensity raises zero by
7".  Go back through and recheck.

Remember that any change in the zero setting later on will require you to
go back through and change the intensity settings, too.  They are
dependent on the zero setting (if that change is large enough).

The soft pedal (hammer rail) should raise such that the intensity change
of the piano is equal to the difference between pianissimo and first int.

The sustain pedal is the most crucial.  It makes the difference between a
great Apollo and an average one.  Pedaling must be clean.  Return speed
is very important.  It must be as fast as actuation speed.  This is done
by adjusting the bleed size and valve gap very exactly, as well as the
height the damper rail is lifted.  Adjust the dampers very precisely to
lift all together, just like you had glued them together or something.
When you just "crack" the pedal, you should see them all "budge" together
at the same time.  Like a row of precision little soldiers, they have to
come up as one solid piece.

These pianos convert to play Ampico rolls with a little change here and
there.  Dr. Bill Flynt wrote an article in AMICA years ago explaining how
that was done, I believe.  Unless you have a library of rolls for this
piano, it is very doubtful that you will ever find any Art-Echo rolls.
I don't know what your purpose or intended use will be, of course.

Terry Smythe was correct to ask about conversion to another reproducer
format if he expects to play the piano after all the work it takes to get
them going.  I have also converted one to play Ampico rolls, using my own
devices.  It can be done without a lot of changes.  As I recall, now, the
only original device changed was the metering pin hole and removal of the
pin brake.  If you want to, you can just remake them and leave the
original ones in the piano for future use.  Then by retubing the
trackerbar around, you have an Ampico system.

Nothing has been changed this way, except the format the piano is able
to play, and you can now find rolls for it.  Then by leaving everything
original otherwise, your documentation in an envelope somewhere in the
piano will instruct a future buyer as to how it may be changed back -- or
yourself -- if rolls become available.  If I recall now, the differential
pneumatic controlling the metering pin is given a spring to return it to
zero intensity and by adding a few pouch cutouts and a couple of block
valves you have an Ampico system.

Craig Brougher


(Message sent Fri 8 Aug 1997, 13:42:24 GMT, from time zone GMT.)

Key Words in Subject:  Adjusting, Apollo, Art-Echo

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