In response to Robert Gates (MMD 111126) and Ralph Nielsen (MMD 111117)
and others, some information needs to be shared, along with a few
opinions.  Before I start, let me say that I am a big fan of Aeolian,
but that does not stop me from criticizing them.

The Duo-Art piano system had many upgrades during its production life.
One of those upgrades was the keyboard shifter, or una corda mechanism.
Prior to 1926, the Duo-Art grand pianos incorporated a hammer rail lift
only, or half blow in English terms, that fulfilled the soft pedal
function commanded by hole #95 of the tracker bar.  In 1926, Aeolian
started putting both the hammer rail lift and una corda shifter in Duo
Art grand pianos.  That means that many of the Duo-Art grands built
have the keyboard shift system.

Most original factory tubing on all pianos that I have seen, connect
the una corda shifter to the tracker hole #95, while the hammer rail
is connected to the "Soft" switch.  But Aeolian was inconsistent and
exceptions can be found.  On upright and grand pianos, there might be
extra nipples on the keyslip "Soft" switch, and sometimes, the hammer
rail lift pneumatic on uprights even has a pallet valve that "might"
be tubed to the #2 Accompaniment accordion.

So what do all these confusing options mean?  Basically, the owner
should select an operating option and regulate the piano to sound right
with that option.  Pat DeWitt's request for a one way check valve
scheme introduces a new option, which would add to the confusion.  It
certainly is not original.  With multiple nipples on the "Soft" pallet
valve or a pallet valve on the "soft" pneumatic, a one way check valve
is not necessary.

And most recently, concern has been raised over shifting the keys while
the poppets are raised.  This is not an issue.  The keys don't move
that much, and they easily slide over the raised poppets.  Even if they
don't easily slide, no harm will come to the poppets if they are
properly aligned as there is enough play and flex to allow reliable
operation.  The whole keyboard moves about 1/8 inch.  The keybacks and
poppets can tolerate that movement easily as the poppets will contact
the under key felt throughout the full range of the shift.

In my opinion, there should be no connection to the #2 Accordion when
the roll triggers the soft pedal mechanism through tracker hole #95.
However, if the keyslip switch is placed in "Soft", and the hammer
rail is raised, it is possible that some notes might skip unless
the accompaniment level is slightly raised.  It all depends on the
particular roll coding, as the Duo-Art is dependent on coding to
maintain a proper minimum vacuum level.

And yes, turning on the #2 Accompaniment does mostly negate the effects
of the hammer rail lift in the softest passages of the music.  Like
most reproducing pianos, using the "Soft" position is mostly a gimmick,
and takes away the realism.

Now, if you think the folks at Aeolian left a trail of confusion
concerning the soft pedal, read the next article about the Aeolian
Duo-Art Echo OrganEcho organ.  That subject is _really_ confusing!

Bob Taylor
Columbia, Missouri