Hello to all you experts our there.  I have rebuilt a Duo-Art grand
piano and for the most part it expresses well and all of the pressures
are in the range suggested by Mike Kitner.  I would, however, like to
reduce the volume level of the piano when playing at the loud level or
with the crash valve open.  I have experimented with bleeding air into
the main pump line and also reducing the speed of the pump.

Both of these did work to lower the overall volume; however, the main
pump vacuum is strongly affected by the amount of air bled into the
system by the roll motor, which is variable and a function of the speed
setting.  Thus when I get the system set up for one speed but the next
roll calls for a faster speed, I find the feed vacuum is inadequate.
Any suggestions?

I am also looking for a sub-bass box for an Aeolian Grand reed organ.

Thanks

Howard Towlson