My thanks to Messers Taylor, Wolff and Walter for their kind words in
MMD 15.09.24 regarding my posting in MMD 15.09.23 about what I termed
the "Mystery of the Missing Ampico Intensity".  First, apologies to
Bob for an apparent less-than-thorough viewing on my part of his
excellent DVDs about all things Ampico.  I have both of them and can
heartily attest to their worthiness and necessity for every rebuilder's
reference shelf.  But I can assure Bob and others that I arrived at
my "discovery" quite independently, whereby the absence of the 2&4
intensity combination fairly leapt off of the page of the 1929 Service
Manual's Figure #10, aided, no doubt, by the graphical presentation,
absent in earlier Ampico manuals.

My "go-to" technical reference is Frank Adams' 1973 green hard-bound
compilation of four manuals, the 1923 "Ampico Inspector's Reference
Book, the 1929 Service manual, the 1925 Duo-Art Service manual and the
undated Welte-Mignon "Instructions ...".  I'll take Bob at his word
that the 1919 update of the Inspector's Reference Book uses the term
"Alternate Setting" for the 2&4 combination, but I'm not finding it in
the 1925 version.  My copy of the 1919 version is presently packed away
somewhere and unavailable for review.  Bob, I promise I'll dig out your
DVDs (they're probably with the 1919 manual) for more thorough review
so I don't "reinvent the wheel" on other topics.  Your picture of the
factory tag on the RCC Mason & Hamlin is pretty much definitive on the
subject of "1st Intensity".

I agree with Lester Wolff's assertion that most Ampico owners (and
other systems for that matter) have only a passing knowledge of the
technicalities of "dB" as it relates to intensity of sound, and that's
okay.  I happen to have a very nice "Sound Pressure Level" meter but
I have never used it to adjust any reproducing mechanism I have rebuilt
or maintained, nor would I.  Duke Ellington once remarked, "If it
sounds good, it _is_ good." Dr. Hickman would have, no doubt, agreed.

Good piano tuners, (a skill I do not have and do not plan to acquire),
typically use electronic aids to set the "temperament octave" but
everything after that is done "by ear".  I rarely, if ever, start an
adjustment process with a vacuum gauge, save for the basic pump spill
level.  I have a few favorite rolls that I "know" how they should
sound, and I adjust the mechanism to that standard.  So much of the
performance depends on the piano, the hammers, the stringing, the size
and acoustics of the setting, etc., that specific readings in the
manuals should be considered no more than general suggestions, not
inviolate values to "set and forget".  After I'm satisfied, I may check
the resulting levels out of curiosity, but only that.

Mike, I had to chuckle at your characterization of my posting as
"[going] to great lengths to explain [my] philosophy about the Ampico
systems and ..."  I actually tried to _avoid_ anything "philosophical"
in my discussion, to concentrate on the purely technical aspects of my
observations.  I also second your opinion of Bob Taylor.  If he and I
ever disagree, take his word.

John Grant