Damon Atchison asked about how many expression levels the Ampico has.
The most direct answer is seven.  However, the direct answer is also
wrong.  The (so-called) crescendos are able to raise the pump level
from the nominal 20" (which is reroll level) to the top pump level
(depending), say from 32" to 40" or so.  That part of the circuit is
analog, so you might say that you have, in effect, an infinite number
of steps between pppp and ffff.

Duo-Art has sixteen 16 different levels of expression, while Ampico has
only seven.  However, Duo-Art normally didn't use real-time "on the fly"
expression, either.  So for the most part, Duo-Art was a binary changing
machine.  That was ok, since the finest musicians can only detect about
seven or eight discrete expression levels, anyway. (I realize we think we
are much better than that).  But the stuff in the music that really makes
the difference is the phrasing and pedaling.  That takes an instrument
that has been thoroughly fine-honed and fussed over for weeks!  You do
_not_ achieve that in a couple of hours of adjusting.

The actual number of steps of expression isn't really that important in
reproducers, as long as there is also an analog component involved.  The
human brain and fingers combine to build a system which is both digital
and analog, too.  One day, computer engineers are going to realize that
their logic has been fuzzy (that's really bad, I know) and will decide
then to incorporate analogic into some of their transducing.  I think
they have already done this in many applications.  In other words, more
and more they will start to "put the 'feel' back into their stuff."

Craig Brougher