Benjy Templeton was wondering if the Marque Ampico was missing its
crescendos.

No, actually the Marque was designed as the foot pump version of an
Ampico, and while it was able to produce, probably 20" vacuum, due to a
small treadle bellows and long lever for power it could never produce
continually what the grand rotary pump could come up to, so there was
really no reason to put a crescendo on it, since it was the crescendo's
secondary job to operate the pump amplifier.  If you were to leave the
Ampico grand "Modify" switch at "Medium" or "Normal" (both terms were
used), the crescendo's function of raising the pump pressure above
nominal 18-20" cannot be utilized, anyway.

So a Marque is fully able to reproduce as well as the full-blown Ampico
upright on "Normal" setting.  You will hear practically no difference.
It is only when you switch the full Ampico to "Brilliant" that the
differences are heard.

The "crescendo" in an Ampico is to provide primarily a constant spring
tension, anyway.  It maintains the first intensity as a reference which
cannot be changed by the stack pressures.  (Think of a balance beam
scale with reference weights in one tray that are the standards).  The
rolls normally were cut to do all the expressing in "Normal" mode
without crescendos, otherwise, there would be no difference between
Normal and Brilliant in an Ampico.  The mechanical analogy of first
intensity maintenance _is a spring_, in fact.  And in the full Ampicos,
the crescendos act upon a bellows called the "Spring" pneumatic to do
the same thing.  This is the pneumatic which takes the place of an
actual spring.  So, unless the pump can be increased, no Ampico would
need more than a Marque spring.

If you want to know more about this subject, MMD has quite a bit about
the Ampico crescendos in its archives.

Craig Brougher