Hello MMD and David:  I have recently rebuilt my first Duo-Art system,
so I do not have very much experience, but I have read everything
I have been able to lay my hands on.

As I understand it, US made Duo-Art systems use two different sizes
of springs, with the slightly stronger spring in the theme regulator.
UK-built systems have identical springs for both regulators.  (If my
memory serves me well this was in an article appearing in the AMICA
bulletin some time last year).  Mike Kitner's article on rebuilding the
Duo-Art stresses the importance of keeping the springs in their proper
place.

I was a little surprised to find that the two springs in my US-built
(circa 1927) Steck seemed to have the same strength.  However one has
been wound clockwise and the other anti-clockwise.  Since my instrument
had been partially rebuilt by a previous owner I can not be certain
that the springs are the originals.

Should I be looking for a new pair of springs, or did Duo-Art change
to identical strength springs in the later years?

Regards to all

John Johns
Ottawa, Canada