[ Dave Haibach wrote in 140201 MMDigest:

> The vacuum pumps on Wurlitzer's smaller organs were also quite
> inadequate for all but the best sealed organs, in my opinion.

Our experience has been that the vacuum pumps in Wurlitzer band organs,
small or large, provide ample suction to keep the vacuum reservoirs
pulled all the way shut and spilling atmosphere into the system
continuously in any organ that has been fully restored.

The vacuum pump in a tall Wurlitzer orchestrion (Styles B, C, BX, CX,
or LX) is approximately the same size and has to power more mechanisms
than in a smaller Wurlitzer band organ.  The piano orchestrion pneumatic
stack has more pneumatics (which are substantially larger than the
stack pneumatics in a small band organ), vacuum-operated bass drum and
triangle pneumatics that take more suction than the trigger pneumatic
in a band organ bass drum action, a set of small pipe chest pneumatics,
soft and sustaining pedal and mandolin pneumatics (not present in a
band organ), plus snare drum and bell pneumatics (which use somewhat
less suction in the piano than in the band organ).

The vacuum pump in this type of orchestrion has no trouble supplying
the greater volume required, with the vacuum spill admitting air into
the system almost constantly throughout play.  If the vacuum system in
a Wurlitzer band organ seems weak or underpowered, it isn't in the
condition it was when it left the factory.

We maintain several Wurlitzer band organs located in unheated buildings
that still hold vacuum today as well as they did when restored, some as
long ago as the 1970s.

Art Reblitz - Reblitz Restorations Inc.
http://www.reblitzrestorations.com/