I have in my home an Aeolian player pipe organ (Opus 1181) in my home.
The organ includes a 3 rank Echo division.  The roll player (built into
the console) can play both 116-note and later Duo-Art 176-note rolls.
I have not yet wired-in the Echo division, so I have no experience
hearing how Duo-Art rolls handle it.

In residential installations the Echo division was often some distance
from the primary listening room, and I'm inclined to think it would
most likely be set to play solo, since any but the softest ranks on the
Swell division would drown it out.  However, in addition to the stop
tablets for the Echo division, there is a set of 5 pushbutton switches,
labeled:

  Manual  I - Only
  Manual  I - With
  Manual II - Only
  Manual II - With
  Off

This arrangement implies that for some rolls Aeolian might have
wanted to have the Echo division playing solo (from either manual);
while on other rolls with some stops on either the Great or Swell
divisions.  I have not previously studied the 116-note rolls carefully
to see whether the printed instructions specify "With" or "Only" when
calling for the Echo division.  I'm assuming that they would have
wanted to keep the same flexibility for Duo-Art rolls.

Tracker bar hole # 2 is used for turning the Echo division on and off.
When the Echo division is turned on by track 2, does this automatically
cancel all the stops on the Swell division (presumably through some
mechanism in the jack box)?  Or is this done by perforations in the
roll to individually toggle-off the stops that were previously
activated?

Regarding the Echo division, there does not appear to be any way on
the Duo-Art rolls to specify Manual I or Manual II, so the Echo
division must have been permanently assigned to one manual (probably
Manual II, Swell).  If they wanted the Echo division to play solo, then
all the stops on the Swell division would have been turned off (either
individually or by a general cancel), as in roll 3415.  But perhaps
there are other rolls that do call for some stops on the Swell division
to play simultaneously with the Echo division?

What is not clear to me is if, or how, the Duo-Art rolls would
automatically control individual stops on the Echo division.  There is
no track, for example, for the Quintadina Flute and, to the best of my
knowledge, the other stop-controlling tracks only pertain to the Great,
Swell, and Pedal divisions.

Rich Giaccio
Syracuse, New York