Amica Ampico Article
By Craig Brougher
|Amica Ampico Article: Fifth and final installment of comments.|
9. "Indeed, the Model B device is an amplifier; but it is not a true
crescendo. This single amplifier affects the suction supply to both
'C' pouch regulators simultaneously." p 71, para 7.
ANS: In the first place, Jeffrey isn't aware of the fact that the regulator pouch or curtain in the final Model B Ampico was never called a "C" pouch (stands for control pouch) by the factory. That terminology was reserved for an earlier prototype built about 1925 or so. See pg 239, The Ampico Reproducing Piano, by Richard J. Howe.
The purpose of the comment is actually a rebuttal to something I had said in an earlier article anyway, and doesn't really apply to his thesis. He wants to believe that unless the "crescendo" function can directly change piano loudness without the need for intensities, it isn't a "true" crescendo.
The determination of whether something is a true crescendo or not is dependent solely on the way it was programmed by the roll, and it doesn't matter if one piano required an angelic presence and the other didn't. All that matters is the roll itself. And if both the Ampico 1A and the Model B used a crescendo dependent on the intensities while the Stoddard and Model A had a different setup but they were all used in the same way and the roll made them do exactly the same thing, then what could he possibly mean by saying that one piano had a true crescendo and the other didn't?
Don't take my word for it. Take the word of Angelico Valerio and Nelson Barden who discussed the issue of crescendo oriented rolls on p 128 of The Ampico Reproducing Piano. Valerio: "atrocious." Barden: "Terrible, Just awful." I think they are talking about some of the rolls from the Hupfeld roll series here, because very few Ampico rolls were "crescendo oriented." That is a provable fact that can be literally measured. But some of the recoded rolls by Suskind in a "make-do" desperate situation required, like 10" long slow crescendos, and stuff like that. And the rolls were almost humorous, they were so melodramatic.
The main reason Ampico didn't use the so-called "crescendos" without intensities was because it made the roll too tempo dependent. The loudness of the piano escalated on an exponential scale while the crescendo progressed linearly. That isn't too friendly when your tempo could be off, say, 15%. As a matter of fact, approaching the correct tempo number from the left side, as opposed to passing the number and then returning to it from the right creates about a 10% change, in some cases.
The term, Crescendo was given to these analog ramping devices or "volume controls," from its inception-- long before they were actually used in that way. It was a convenient label that described in a word what they could do, not that they would ever expect to create realistic musical crescendos with them.
Even the 1919 Inspector's Instruction Book explains the use of crescendos only as a "platform" to develop intensities on, and not as a separate musical effect, although earlier rolls made use of them on occasion more than they did after the 1921-22 Standardization. Remember, though, before 1922, they were using a variety of methods for coding Ampico rolls. That means, some would play on a "B' better than others. Later, they recoded all of the top sellers before 1922 so that they would be compatible with what was coming in their new pianos. Since not too many Ampicos were sold before 1920 anyway, there aren't too many early rolls to worry about.
I have ben asked by Linda Bird, presently V.P. of Amica International, to write a correction article to the Jeffrey Morgan Ampico article. It is a little different than these inserts, but technically, about the same. There is a bit more detail in the article itself.
I'm sure I do not have all the mistakes found, yet, but the basic error underlying Jeffrey's "comparisons" is just that he was not aware that the crescendo in both instruments is powered directly by the pump, and that there is no feedback or regulated supply going to it from the stack. From this basic error comes all of his erroneous conclusions. I hope he hasn't been hooking up all his crescendos to the regulated stack supply!
In any kind of a regulator, a reference signal has to be measured against an output signal before any kind of regulation can be accomplished. The reference signal (or desired intensity) must be maintained with close tolerances until the output can be brought up (or down) to equal it. Unless the crescendo pressure can be maintained independently of the intensities and the stack pressure changes, there can be no regulation at all, and therefore, no reproducer.
Without this basic understanding of any kind of regulator, whatever else Jeffrey might say is moot.
(Message sent Sun 26 May 1996, 14:41:33 GMT, from time zone GMT.)