Hi all,  One of my American customers recently called me in to 'tweak'
his Weber Duo-Art upright back into proper expression.  I found it
skipping lots of notes, did some vacuum and test roll measurements and
found that there was not much pressure increase for the louder levels.
Spill pressure was some 34", which I thought was quite high.

I watched the accordions and found them to only collapse about half or
so.  The verdict was that the accordions were completely shot.  They
leaked everywhere and from experience I know that this is due to bad
quality material where the rubber comes of the cloth.

I took the expression box out and rebuilt the accordions in my workshop.
I tested the box on my test bench and made the necessary adjustments to
the accordion travel, the spill closing, etc.  I subsequently fitted it
back to the piano and made the adjustments with the vacuum gauge and
test roll.

It passes the tests and it even passes most of the play/no-play chord
tests at the end.  The crescendo for accompaniment works but seems a
little loud on the second last level, and does not increase in volume
for the last level (=15).  The vacuum does go up a little, though.

I thought the piano to be working quite nicely with a large range from
pp to ff as it should be.  It plays softer than any human could ever
play on some of the pp passages.  All this took quite some time, with
many rolls, etc., to be sure that everything is okay.

The customer told me that he doesn't like it at all and that the
expression has become jerky and poor.

I fine tuned it over and over to try and accommodate him but he is just
not happy and even said that he cannot ever demonstrate it to anyone in
this condition.  Well, I am not sure what to do next because technically
the thing is as good as it can be with the current condition of the
piano action.  Bottom line is that it was faulty and I repaired it.

He can't tell me exactly what he finds wrong with it either.  If I had
to make a judgment, I would say that the piano increases in volume a
little too quickly for the different levels.

Has anyone else got experience with such problems?  What is the remedy
to get this man happy?  I would feel a lot better if he was as happy as
he's been for the past 12 years...

Kind regards
Bernt Damm
Cape Town

 [ A player tech told me that more than once he encountered a weird
 [ sounding Duo-Art and then discovered that it had been rebuilt
 [ without the bleeds at the accordion pneumatics.  -- Robbie