Following on from a couple of replies, the most versatile instrument
commonly found just has to be the Pedal-Electric Duo-Art.  About half the
Duo-Arts here in the UK are of this type, grands included.  My own
instrument, nearing the end of its restoration, is a 6' Weber grand of
about 1931 vintage, and it works equally well for both for Duo-Art and
foot pumping.

Pretty well all the later UK Duo-Arts have '6-pouch' expression boxes in
them -- that is, they have Duo-Art theme pouches as per any Duo-Art box
(going from accompaniment to theme), plus Themodist theme pouches (from
accompaniment to suction supply), plus a pair of cutout pouches to switch
from Duo-Art to Themodist.  Because of this, even Duo-Arts without the
foot pump box can have one fitted, as the rest of the mechanism is there.

Talking to a restorer here, he said that he thought the Hupfeld
Triphonola the best reproducer he had heard -- again, a pedal-electric
choice offered, plus Themodist (and in magnificent Bluthner and Ronisch
pianos as well).  The Triphonola is a full 88-note reproducer, with the
expression holes outside the loud and soft pedal slots.  The rolls look
uncomfortably fragile as a result!  What a shame these instruments are so
unusual.

When it comes to reproducers, the real difference is in the roll editing.
A commonly-held view here is that Aeolian concentrated on classical
pieces, and their dance music, while good, is perhaps lacking a bit in
variety.  The UK operation didn't even bother recording British dance
music.  Ampico offered more styles of dance music.  The two companies
also clearly had different ideas about what they wanted their instruments
to sound like, as the expression coding shows.

 [ The performance confirms this.  Each company's pop-roll product was
 [ edited to conform to their established "sound".  -- Robbie

For instance, you commonly see Duo-Art rolls where the accompaniment is
completely flat at level 2 for ages; this is obviously what the editor
wanted.  Ampico levels seems to move around more -- again, a conscious
choice, not something implicit in the system design.  I'm sure a good
modern roll arranger could make an Ampico have a 'Duo-Art sound' and vice
versa!  It's up to buyers to choose the system they like best - both are
quite superb.

For a long time I have wondered whether attitudes to particular systems
relate not only to how well they work but also non-technical issues.
Ampico seems to have been very lucky, with both Stoddard and Hickman well
known and admired, and lots of original paperwork surviving, together
with some very detailed publicity such as the 1920s Scientific American
articles.  Welte was represented into the enthusiast era by its inventor,
Edwin Welte.

The Duo-Art seems to have missed out here -- the company was secretive
and the inventors are not really known.  How much of the goodwill a
system has is due to its inventors?  Do we accept that the Ampico was
clever because its inventor was around to tell us so, and perhaps
conversely think Duo-Art is not quite as clever because it has no
champion (or even because the Ampico guys said so)?

All this is just idle speculation, of course, but it's an interesting
topic.  History, after all, is written by the winners -- and the greatest
win of all is surviving to tell your story!

Julian Dyer