With all this talk about MIDI and the pneumatic player, I thought I would
throw this ringer in!  I have just brought into my shop the pneumatic
player stack to a MIDI player grand piano!  This is *not* a misprint!

The complaint was that the piano was making a hissing noise while it
was playing a disk.  Huh?!  Well, I went to check the piano.  Get This:

The unit is called the "Piano MIDI-Matic".  It uses a small vacuum pump
(like a Lee or Equivac turbine pump) to supply vacuum to a small
pneumatic stack.  The stack is made of acrylic plastic; the pneumatics
are also acrylic plastic, covered in either Bilon or Polylon.

The valves are small 12-volt solenoids, connected to several circuit
boards mounted on the bottom of the stack.  The sustain pneumatic is a
regular wood-type covered in motor-weight cloth, operated by 2 valves.

The circuit boards are connected to a MIDI (yes, MIDI) interface, which
decodes the incoming note data, then fans out the appropriate note on/off
signals to their respective valves.

Note velocity is not passed - the volume of the entire piano is
controlled by the speed of the vacuum pump (fast=loud, slow=soft) which
is controlled by an electronic speed control mounted at the front of the
keybed.

Has anyone _ever_ seen one of these things?  I _think_ it might have been
made by the same outfit that made my "Organ-Matic" player unit on my
Kimball organ.  ("Matic" was the last part of the brand name on both
units)

I can repair the unit no problem - the front seal tape has let loose,
requiring replacement (which means tearing the stack apart).

If anyone has seen one of these things, or knows about who made it,
I would like to know.

Mike Carey¶
mcarey@usit.net