John Phillips asks about the Estey player with Amphion action.
From the picture it appears there are three sets of dual cutoff
boxes.  My guess is that the _two_ 'H' shaped tees are to couple
a single control signal to the control (on/off) ports on the three
boxes.  If this is so, then the three boxes are used to cut off
six separate pneumatic functions.

What are these functions?  I don't know, but there may be clue
given from the tracker bar.

Paul Rumpf
Melbourne, Australia