I really appreciate Dan Wilson taking the time to answer my questions
in MMD. I am still unsure as to how the theming inverting valve
(inside valve) augments or replaces the normal stack pressure momen-
tarily to the inverting note valve. As you say, the Autopiano stack
is certainly not an ordinary one! I was first going to address this
letter personally, then I thought how interesting it would be to others
as well. So I am just sending it to the forum for these ideas, so
everybody can benefit.
I visualize all these valve plates sitting in normal stack vacuum, all
connected to the same supply as in the case of the ordinary Autopiano.
But if they are somehow supplied individually when their theme accent
arrives, they couldn't be connected together, but somehow isolated
instantly, then switched back.
The only way I can imagine to do this is by first providing a sort of
honeycomb isolator wall for each valve in the stack. Then placing the
theming inverting valves above (or wherever...) the note valves with
their pouches in theme pressure, and their outside valve plates in
normal stack pressure (a sealed inverting valve). The outputs of
each theme valve would supply each individually supplied note valve
that way, but then, two stack vents wouldn't really be required since
everything is individually supplied through the theme valves "either/
or" system. The supplies would then go to the theme stack for
distribution. The note valve pouch bleed and valve would be supplied
by whichever supply the theme valve was switched to, at the time.
Am I getting warm? By the way, it is hilarious to me, but it is
certainly the most novel player piano system I ever heard about!
You could forget about tracking a roll on this system. No roll tracker
would even budge the paper on that bar! Talk about a clamp.
Regarding the coincidence of unwanted note themes, I still have my
doubts. This system by necessity cannot turn things on and off
instantly, and so, just as in the case of other reproducers, small
delays in theme timing still result in a portion of the accent going
to unwanted notes just the same. Theme perfs (on some more recently
coded Duo-Art rolls) that have been aligned with the desired accented
note on the note sheet, or even 1/16th behind it still accents the
right note, as the surge of vacuum begins during the note strike
instead of just before it. (It isn't the ideal, and you don't get all
you purchased, but it still does it). This would also happen to the
If each column of holes contains 9 adjacent notes being bumped in
quick succession, then there are far more opportunities to accent than
just a simple downward glissando or half note runs. Debussy and Ravel
would have probably hated the idea! It would be "educational" to hear
something like Reflects Dans L'Eau or Gardens In The Rain. No wonder
the rolls consisted mainly of "military" classics and Edwardian pops.
It would be a great piano to play melodramas on.
The musical portion of the idea still sounds like playing a pinball
machine by shooting all balls at once and then shaking the table so
that the balls only hit the lights they're supposed to hit. "It's
really easy, once you get the hang of it!"
[ I will put some Kastonome photos and drawings at the
[ MMD Tech site, http://mmd.foxtail.com/Tech/ -- Robbie