Hello All,

    The discussions on the list in the last several days regarding the
playing of reproducing rolls on 88-note instruments reminds me of the
way I solved this problem several years ago.  For those who have back
issues of the AMICA Bulletin, it is documented in the April 1982 issue,
page 70.  For those who do not, I will attempt to describe it, but this
is a case where one picture (diagram) is literally worth a thousand words.
If it is still unclear, email me your snail mail address and I will send
you a photocopy of the article.  The actual photos probably will not
reproduce very well, but the words and line drawing diagram should be
sufficient.

    Materials needed:

        - Duo-Art style 8 signal (2 x 4) cut-out block.  These are the
          gadgets which inhibit or allow the intensity signals to be
          passed through from the tracker bar depending on the position
          of the Duo-Art Off/On switch.  On the 88-note stack Duo-Arts
          there was a second unit which inhibited/allowed note numbers
          1, 2, 3, 4, 85, 86, 87, and 88, again depending on the position
          of the D-A On/Off switch

        - Ampico A style "Modify" switch.  This is the switch at the top
          of the row (in the typical "A" drawer) that has three positions:
          Brilliant/Normal/Subdue.

        - 4 plastic "y" couplings for tracker bar size tubing.

        - 2 #60 drill hole bleed cups

    Now, the attempted description.  Use section 1 of the cut-out block
to inhibit or pass notes # 1, 2, 87, and 88.  Use section 2 to inhibit
or pass notes # 3, 4, 85, and 86.  Number the nipples on the Ampico modify
switch as follows:  #2 is the nipple which is opened to atmosphere when the
switch is in the "Brilliant" position.  This is usually the middle nipple
in the grouping.  #'s 1 and 3 are the other two nipples which are opened
to atmosphere when the switch is in the "Subdue" position.  Which you
label #1 and which you label #3 is unimportant at this point.  Now, connect
one leg of "y" #1 to a constant (during "Play") source of vacuum such as
the primary stack (if present) or the tracking regulator supply.  Into
the other two legs of this "y" force the two bleed cups and connect each
of these legs to two other "y's" (call them #2 and #3.)  Connect one leg
on "Y" #2 to section 2 of the cut-out block.  Connect the third leg of
"y" #2 to switch nipple #1.  Connect one leg of "y" #3 to section 1 of
the cut-out block.  Connect the third leg of "y" #3 to one leg of "y" #4.
(Are you still with me?!)  Connect the two remaining legs of "y" #4 to 
nipples 2 and 3 of the switch.

    Theory of operation:  When the switch is in the "Normal" position,
none of its nipples are opened to atmosphere and the constant vacuum
passes through the bleeds and enters both sections of the cut-out block,
raising all the pouches and allowing tracker bar signals for all of
the 8 notes to be passed.  This is the position to play 88-note rolls.
When the switch is in the "Brilliant" position, atmosphere is admitted
into the tube which pulls up the pouches in section #1 of the cut-out
block which is controlling notes # 1, 2, 87, and 88.  Since this is
"downstream" from the bleed, the vacuum through the bleed is negated,
and the cut-out block inhibits those notes.  This is the position to
play Ampico rolls.  You will still get one spurious note (if you choose
to allow it,) that being the "rewind" hole which lines up with normal
note #86.  When the switch is in the "Subdue" position, both sections
of the cut-out block are activated and all 8 notes will be inhibited.
This is the position for Duo-Art rolls.  Welte rolls (9/inch)can also
be played on this position, however, low C, if called for by the roll,
will not sound.  A more complicated cut-out arrangement would fix this,
of course.  For one note (and the few Welte's I have to play) I did not
bother.

    This does away with the bothersome taping of the tracker bar which
can itself, in a sensitive mechanism, cause spurious notes.  And, there's
no messy adhesive residue clean up!

        Season's Greetings to all readers.  -John Grant

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"Every creative act results from a sudden cessation of stupidity."  
 -Edwin H. Land, inventor of the Polaroid Land Camera¶
"Help stamp out and eliminate superfluous redundancy." -Genius¶
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