I'm helping a man with an Autopiano player system that has the Reostyle
expression switch (see pictures below).
If anyone knows how this switch is supposed to be tubed to the system,
please contact me. There are a few things that are odd about the system.
First, the only obvious "expression" devices in the piano are the regular
Bass and Treble Soft devices and the Sustain device. Second is the note
in the M.F. position of the Indicator, which reads "Here when using
buttons." This would seem to indicate that the Reostyle switch controls
the operation of the Bass and Treble Soft devices in one of the five
positions. Third, the system also a pneumatic cutout pouch as opposed
to a mechanical cutout, which is more common in an Autopiano system. And
it has a Silent pushbutton.
Looking at the pouch-operated cutout, what comes to mind is the choker
device that Durrell Armstrong created for controlling the volume of the
piano when using a constant speed vacuum pump. By admitting a metered
amount of atmosphere into the pouch well, the position of the pouch could
be controlled, which would limit the air flow. Judging by the small size
of the holes in the switch, they might be used to control the pouch.
Anyhow, any suggestions are welcome.
John A. Tuttle
[ Reostyle Indicator
[ Reostyle Switch
[ Reostyle Tubing
[ Cutout Valve