Development continues on my invention that will aid in better
performance of Ampico A rolls played on the Ampico B.  The deficiency
of the B piano to properly play some A coded rolls was known by Dr.
Hickman before the first B piano was sold.  In attempting to avoid those
issues of incompatibility, Ampico started releasing the B coded rolls
two years before the B pianos were sold.  But that doesn't help those
of us who collect -- our rolls come from all sources and some rolls
come from the early "A" era.

I first announced my development on MMD 17.03.04.  At that time testing
had just started.  Since then, the first prototype has been discarded
and replaced with a new device that now has four control tubes.  The
additional tube helps the logic device stay inactive when soft playing
is in progress.

A YouTube video is now available giving a short demonstration.  "Danse
Macabre", a roll from 1917, is used to show how my logic device helps
solve the compatibility problem on that roll.  Feedback is welcome.

https://youtu.be/ZyFrUQz6KM4
 

Bob Taylor
Missouri