Unlike the Duo-Art and the Ampico, the Welte Licensee system seems to
be set up to build up to a preset vacuum level controlled by a spring
loaded spill valve and stay there whether the piano is playing loud
or soft.  If so, what is the expected pump vacuum level that would be
found in the typical Welte?  I'm sure the setting varies from piano to
piano, but it should fall into a certain range.

Dick Merchant
Carlsbad, New Mexico, USA