Dear Folks,  I am following up on Spencer Chase's (030502, 030503) and
Nicholas Simons' (030503) recent posts regarding the engineering and
design flaws of the Aeolian Duo-Art.  This is obviously a discussion
worthy of this forum, but I would like to see greater specificity in
the claims and statements being made.

For example, Spencer's post of 030504 states that the Duo-Art design:

"... placed a tremendous burden on the editors, whose job would have
been greatly simplified with a better design."

This happens to be true, but Spencer does not articulate the design
"flaw" that makes this statement true, which is that the Duo-Art does
not have "regulated" vacuum to the system as a whole such that each
additional note being played on a Duo-Art causes vacuum "droop"
independent of that caused by the expression coding.  When trying to
code expression, the hapless roll editor has to account both for
expression levels depleting vacuum as well as depletion that depends on
the number of notes being played (as well as sustain and soft coding,
which also cause droop).  Spencer alludes to these issues in a
different context in his submission on emulation (030502), but I think
we should try to be as clear as possible in each our postings.

The above seems to be a _system design_ flaw or _engineering_ flaw
with regard to the Duo-Art reproducing piano system.  Spencer is talking
about something else -- maybe construction or implementation of the
design -- when he says, "the Duo-Art system is the most difficult
to maintain."

I would like to see Spencer, or Nicholas, or anyone else, comment
on the system design/engineering factors separately from the
"construction" factors.

For what it's worth (probably not much), here is my own thinking as
an owner and "tinkerer" who owns both a Duo-Art grand and a Welte
"Original Built" grand:

SYSTEM DESIGN & ENGINEERING: (Duo-Art)

I think the theme/accompaniment
system is great, and really helps with coding and achieving life-like
performances.  I also like that the expression is not "timing dependent"
like the Welte and Ampico.  The non-regulated vacuum issue, though,
drives me nuts, if I am trying to code rolls (not a lot folks are doing
this, so this shouldn't concern many).  I also agree with Spencer that
every aspect of the Duo-Art piano (reproducing mechanism and piano) must
really be in perfect "sync" and working order, but very much disagree
with him that the system is difficult to maintain.  My belief is that,
once set, the Duo-Art system stays pretty static.

I think one should also inquire: what reproducing system _doesn't_
require near perfect regulation of all aspects for best performance?
Spencer apparently believes other systems have more "lee way" but I'd
like him to articulate what aspects of other systems can be "sloppy"
with regards to restoration or maintenance while still delivering an
optimal performance.

The "rabbit ear" tracking device is better than some (i.e., a Pratt-
Reed with the pneumatic flanges on the take-up spool), but not as good
as the Standard / Deluxe "four hole" system.

The set-up of the levers for creating your own "expressive" performance
(1/2 of the "Duo" in Duo-Art) have too many linkages (at least on my
grand), making it difficult to create a good "manual" expressive
performance (as compared to a good quality pumper piano).  However,
I should be thankful that they're there at all, as the Welte and Ampico
permit no meaningful addition of expression (nor tempo, I might add).
With Welte and Ampico, it's "their way or the highway."

CONSTRUCTION & IMPLEMENTATION: (Duo-Art)

The Aeolian mechanism and the pianos they put them are virtually
bullet-proof.  The parts are almost all of very high-quality, tough to
damage, great wood, thick solid spool box, etc.   One gets the sense
that you could throw the piano off a truck and it would be fine.

I also think that once the system is set, it "stays set," with just
an occasional tightening or loosening of the expression springs for
optimal performance of the specific roll with regard to period of
manufacture (early, middle, or late period) and country of origin
(USA or United Empire).  I also find that you can still get a good
quality performance without the "tweaking," so don't do this very often.
The piano is generally set for "late" because these are usually the
best-coded rolls, and I'd rather have the optimal rolls get the optimal
setting...  (Does that make sense?!?)

MEDIA: (Duo-Art)

Terrible paper used, often crumbling due to acid content.  As someone
commented a few days ago, though, the British Aeolian rolls appear to
have used far better content, and are often still in good shape.
However, the wooden spool flanges seem immovable, which does cause
problems if the roll is not in perfect shape (mistracking during play
causes damage rewind because you can't move the spools to accommodate
the variance caused by the mistracking on the "front end").

SYSTEM DESIGN & ENGINEERING: (Welte)

I think the Welte expression system is well-designed, and can deliver
great performances.  On my "Original Welte-Built" (made by the successor
to the German-owned US Welte subsidiary after WW1), I particularly like
the ease with which low volumes are achieved, probably due to the
excellent double-valve design for the striker pneumatics (which may in
turn be laid at the feet of the Standard or Auto-Deluxe companies, who
I think made a lot of the parts for this piano).  I like the "4 hole"
tracking device and thinks it works best.

The rolls are coded, though, with great variance, even within certain
time periods that you might think would make for uniformity in roll
coding (i.e., Red Welte transfers, Poughkeepsie recordings, early
Licensee, late Licensee, etc.).   I basically "set" the piano
differently when playing rolls of different periods (I'll play rolls
of a given period for a few days, then readjust to play rolls of
another period for a few days, etc.).  Though I do this _occasionally_
with the Duo-Art, with the Welte, it's absolutely critical to get a
good performance.

Correct tempo is crucial when playing Welte rolls, but because the air
motor is flimsy and of poor quality, it's difficult to achieve this.
In fact, I've since replaced the air motor with a Bodine electric
motor, and have a hand-held tachometer with a rubber wheel that I place
briefly on the roll as it plays at the beginning, so I can insure the
proper tempo (In case you're wondering, I still have all the original
parts, including the air motor and vacuum pump, that will always be
kept with the piano pursuant to the terms of my testamentary
documents).

To question whether the Welte "floating crescendo" system is "good"
is really to question the entire framework of the Welte system --
something I would not do.  All of the reproducing piano systems can
deliver tremendous performances in the context of a properly-restored
and regulated instrument and well-coded rolls.  I would say, though,
that if the Welte folks intended to have a timing-based expression
system, then they really should have worked harder to insure that the
owner could achieve the correct tempi.

One other gripe on this score:  it is clear that the circumference
of the take-up spool is significantly smaller that the take-up spool
on the recording devices used when the Welte rolls were made; roll
acceleration is a significant problem on longer rolls.   This is
not a significant problem with Duo-Art classical rolls.   (NOTE:
I understand the electric motor may be exacerbating the problem, as
take-up spool load will not slow the roll down as with an air motor,
but trust me when I say the air-motor was far more untenable as a
general matter).

I would also add that to really get the Welte regulated as per the
test roll (and, specifically, to get the Welte to pass both the
forzando "on" test, i.e., it comes on to the correct distance, while
also getting it to pass the "6 step" forzando test that is supposed to
end at the mezzo forte hook at the end of the six steps) , one probably
needs adjustable bleeds on the expression control valves, as Spencer
suggests in his 030503 contribution.

Finally, I think that, for whatever reason, the Welte's expression
regulation is far more susceptible to change due to humidity,
temperature, and perhaps even astrological changes ;-) It is d___
frustrating, but I am constantly underneath the thing tinkering with
the forzando on timing to get it right, after it was okay a month
earlier.  For whatever reason, the crescendo "on" and "off" seem
pretty static, but oh that forzando...  It is about the Welte
system, not the Duo-Art, that I would say "... it is the most
difficult to maintain."

CONSTRUCTION & IMPLEMENTATION: (Welte "Original Built").

I think this Welte (stack above keyboard, no drawer) has some really
flimsy parts.  It is not "bullet-proof."  For example, the key cover
lever and assembly are connected via a tiny 1/4 inch piece of wood
that is begging to break (okay, the left half has broken).

The spool box and all of the other "front of the piano" parts sit atop
a very weak piece of quarter inch wood that spans the width of the
keyboard.  Besides the air motor, this weak and pliable wood also
accommodates the tracking device, air motor, air governor as well as
the lead tubing that leads to two junction blocks that also sit on this
wood.  The theory behind this is not bad..., if you separate the
junction blocks (lead tubing to tracker bar one side, all tubing going
to stack, expression, etc. on other), you can, _in theory_, lift
everything out and get right to the conventional piano action.   Thus
the design here is actually smart, but the implementation of that
design is not.  The fit of the tubing along the sides is far too tight,
and every time I have to work on the piano action (which is more often
than I'd like, because the piano is none too sturdy), many many tubes
become disconnected as I try to get the piano action out past the
tubing connected to the back half of the junction block.

The question is "is this harder or easier than having to disconnect
all of the tubing to remove the action in a Duo-Art grand"?  Well, the
Aeolian product never requires the constant fuss that the "Original
Welte Built" does, so I wouldn't know.  A technician that recently
came to the house to help me with the Welte said, by the time he was
done, that he'd rather have taken out the Aeolian action.

MEDIA:  Welte rolls seem to be made of better quality paper than
Duo-Art rolls, and are usually in better condition.  This is true for
all of: Poughkeepsie "Auto-Deluxe" rolls, Purple Seal rolls and
Deluxe/Welte Licensee rolls.  The Poughkeepsie and Purple Seals seem
most durable, though.

Caveat:  I am not a technician, and I have not carefully parsed every
word above, because I wanted to get this submission in to start the
ball rolling on these sorts of issues.  I think this is a great and
timely topic for discussion, and I hope folks will contribute their
own thoughts, "war stories," etc. regarding the design and construction

Best regards,

Tim Baxter
Atlanta, Georgia