Working with a recently rebuilt 1915 Duo-Art Weber upright, when
playing some standard 88-note rolls, the vacuum level falls from
40 inches to under 6 inches (below the zero level) when six or seven
large chords are played rapidly in succession.  The last chord may
not sound at all.

This is with the Duo-Art switch set to OFF.  Regular Duo-Art rolls
play well, and very loudly.

I am thinking of adding a reservoir bellows to take provide some backup
vacuum.  Any thoughts?  The steamboat pump is doing over 80 inches and
other vacuum levels are well within the bounds of Mike Kitner's
monograph.

Joseph Osborne
Carlisle, Pennsylvania, USA

 [ From your description, it seems the system needs a suction regulator
 [ at the pump such as Ampico and Welte-Mignon have.  I don't know
 [ whether an added reservoir would have enough effect.  -- Robbie