Hello, This is my first time posting.  I have a late 1920's Marshall
& Wendell player with the Ampico A system.  My grandfather rebuilt the
piano in the vicinity of 1970 and nothing has been done to it since
then.  About 10 years ago it played, albeit not so great.  Now it
doesn't play and gets worse every time I run it.

The first time I played a roll recently, only a few keys near the
center played while the others just moved a bit.  After just a few
more minutes of playing and some testing of the stack, etc., no keys
move anymore, although the wind motor turns if you set the tempo high
enough.

I have replaced all large and medium tubing.  The other tubing seems
decent.  I am thinking I should start at the beginning and test vacuum
from the electric pump now.  Any thoughts?

My goal really is just to see this thing play again.  I have no
intention of rebuilding every component.  I have no experience with
rebuilding pianos but am an engineer and mechanically inclined.

My understanding is that, with the amount of valves in the stack, this
is likely a big source of problems.  I have done John Tuttle's test of
the stack by sucking hard on one of the supplies to the stack, with the
tracker bar taped over, and I can suck a lot of air quickly.

I am reading Arthur Reblitz's book; at the moment I am trying to learn
something about the primary valve chest.  Reblitz seems to gloss over
this.  He says, "The Ampico A has a double valve stack, with a separate
primary valve chest."  Then I see no more mention of the primary valve
chest.

Is there a particular name for it, so I could find described somewhere
else in the book?  Or do you know of a good reference on the Internet?

Thanks,
Ron Evans
Verdigris, Oklahoma

 [ Piano
 [ http://www.mmdigest.com/Attachments/14/11/15/141115_111236_IMG_1892.JPG 
 [ Stack
 [ http://www.mmdigest.com/Attachments/14/11/15/141115_111236_20141114_143523.jpg