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MMD > Archives > January 2002 > 2002.01.20 > 08Prev  Next


Power of Duo-Art, Ampico and Solenoid Pianos
By Craig Brougher

D.L. Bullock has made the best and most correct point yet about the
performance of solenoids versus pneumatic players.  I guess he and
I agree fully about it.

I think I said at one time that pneumatic reproducers are a musician's
piano, whereas the solenoid players are fine for the majority of
listeners, as long as they didn't get too picky.  Lovers of Disklavier
cannot be faulted because they've not ever really heard the differences
between a fully restored and perfect Duo-Art or Ampico, and a Disklavier.
But someone really should point out these things, and let people know
that there is after all, such a thing as "best." Americans tend to be
satisfied too often with, "Good enough for who it's for."

Whether or not all models of Disklavier would smoke when the Ampico
roll Bolero was played through them, I can't say for sure.  It was
rhetorical.  But it would be far from handling it, and everybody would
stand around and shake their head at what was happening.  That I can
promise you, because the current carrying capacity of the system isn't
capable of it.  Nor is it capable of playing all but the simplest
Rachmaninoff rolls.  It doesn't have the overall power to even
approximate it.  I doubt that Yamaha even sells the Hungarian Rhapsodies
in its music, and if it does, they are probably watered down versions
or popularized arrangements.  Ravel and Debussy would pass with flying
colors.  There are many classics that Yamaha can manage very well.  But
the heavy classics, I doubt that you will find.  There's a reason for
that.

In any reproducer that is limited to only certain pieces, you would
never even consider that brand if you were a true musician, because
quickly, you would also be hearing the deficiencies glaring at you,
even in Debussy and Ravel.  The human ear is an almost perfect
comparator, but makes a lousy gauge.  So what you don't hear is often
acceptable, as long as something close by isn't available to compare
it to.

Regarding Ampicos being less able to play loud than Duo-Arts, I want
to address that one, too.  That is most likely true with the rebuilt
Ampicos in whose pumps the original inside flaps and seats are still
being used.  Duo-Art used a very heavy strap of prestretched boot
leather for a single inside flap and leather suede seat, whereas Ampico
(in the most used configuration pump) used two lighter flaps and two
seats.  Because of the condition of Ampico's lighter weight leather and
double flap system, the natural decay has subtracted roughly 10-15
percent from the overall capacity of that pump.  That isn't accurate,
of course.  I'm just asking you to imagine.  But it cannot reach the
capacity it did when new, unless rebuilders start replacing everything
in each pump they restore.

Also, in the Ampico, The setting of the amplifier is adjusted to a
specific level for the piano it resides in, and often this was throttled
by the factory on purpose.  If you know what you're doing, you can
change it to achieve the full power of the individual piano it plays.
Ampico wanted a more tame, softer playing instrument because I'm told
that Charles Stoddard had a hearing problem that included ringing in
the ears and was sensitive to pianos playing loudly, anyway.

The third reason is usually because rebuilders did not replace the
pouches in the valve blocks, therefore they did not reseal what looks
to be a thick, shiny coating of heavy bodied shellac on the blocks.
But if you will just place your tongue up against the end grain of
these blocks, wet it good, and then suck on the block sides, you will
feel dozens of little bubbles, bursting against your tongue.  That'
called leakage, and multiply that by two sides, times all the blocks in
the system, and you can deduct another 10% or so.

The fourth reason D.L. is right is because the Ampico model A intensity
springs are overstretched and in time, weaken down.  The most important
movement of that spring is the first 1/8th inch, and there is where the
problem is on all overstretched springs.  Replace the springs with a
new set from Player Piano Co and many restored Ampicos suddenly change
their entire personality.  They are no longer the "quieter player" that
many owners thought they were, especially after you have readjusted the
amplifier system to match the piano dynamic.

It might be interesting to mention that in the case of a few concert
grand reproducers, the Ampico system will play the 9' 6" Knabe concert
grand to its capacity with a fully restored pump turning just a little
over double-speed and the amplifier/spill readjusted a bit.  Whereas
the Duo-Art cannot play realistic heavy classics with a single pump on
a full 9' concert grand because of the intensity step shortage.  The
Ampico concert grand has no shortage of steps in the wider range of
pressures required.  So Duo-Arts on stage possibly were used mainly in
the popular venue, and/or had specially cut rolls and selections that
would not be shorted in performance by having only 16 intensity steps,
all told (there are many ways for a musician to arrange that,
legitimately).

The Duo-Art concert grand requires two rotary pumps and motors or one
large box pump off stage, operating a little faster than usual, whereas
the Ampico required only one regular rotary pump travelling at twice
the speed.  That is not to say the Ampico company didn't also use two
pumps.  But I have heard one of my concert grands play in a large hall
with just one pump and it filled the hall with piano power all by
itself.  It was playing at times to its full capacity.

As you can see, there are more ways of looking at overall power and the
reasons why an Ampico may commonly be lacking.  Restore them fully,
seal their blocks, replace their flaps and seats, and replace their
expression springs, and they are not weak or lacking at all.  They are
equal to the Duo-Art in power.

The Duo-Art gets all of its expression and characteristics from the
roll.  The Ampico is self-compensating.  So the Duo-Art expends a huge
portion of its pump vacuum all the time throughout the music, to the
room.  It is very wasteful in this regard.  That's why it requires a
larger capacity pump than Ampico to begin with.  It's spill setting
depends strictly on the expression step it's on momentarily, whereas
the Ampico spill depends on its reserve and pressure called for to
self-compensate.

Craig Brougher


(Message sent Sun 20 Jan 2002, 16:56:30 GMT, from time zone GMT-0800.)

Key Words in Subject:  Ampico, Duo-Art, Pianos, Power, Solenoid

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