Hi All,  This is just a heads-up message.  It's a proven fact that the
amount of noise produced by a vacuum motor is directly related to the
amount of air being moved.  Ergo, if your instrument/mechanism is
relatively air-tight, less air will flow across the turbines in the
motor and there will be less noise.  If you don't believe me, cap off
the motor with your hand and then remove your hand.  You'll get the
picture...

To improve the sound-to-noise (music verses pump noise) ratio even
further, the vacuum pumps I sell have a voltage controller that varies
the speed of the pump in both the play and rewind cycles (two needs:
two settings).

Look at it this way; If you have a unit that has a leakage factor of
20%, and you generate just enough vacuum to overcome the leakage, much
less air will flow across the turbine blades than if the pump is
running at 100% and the excess vacuum is bled off to the outside
atmosphere.  Truly, vacuum pumps used in leaky player pianos represent
a case where "more is not better".

Musically,

John A. Tuttle
www.player-care.com
Brick, NJ, USA