When rebuilding an Art-Echo reproducer, and knowing the customer could
not find rolls, I retubed it so it could play Ampico rolls, instead.
But while it will sort-of simulate an Ampico, it is not, as many
believe, just an Ampico tubed in reverse.

I think the thing that made some people believe this, was the faint
similarity to the Ampico "crescendo" and the metering pins that Art
Echo used.  That is where the similarity stops, however.  So to make
an Art Echo play Ampico rolls fairly well, you have to modify the
metering pins and their circuits.  Add two more valves, some cutout
pouches, a couple of springs, and "T" together some of the expression
tubing.  And, yes, I modified the metering pin hole length and diameter
too.

The basic problem is, Art-Echo had a circuit called "diminuendo."
It was used to return the metering pin.  Ampico didn't need that,
since they had their first intensity regulator spring doing it.  So
if you are going to change the Art-Echo system, you will have to have
a self-timing crescendo system like the Ampico.

Also, B8 and T8 tie together, and operate off of T4 without a cancel.
B6 and T5 aren't used, so the dual pneumatic diminuendo must be spring-
loaded toward soft  to balance, or equalize the separate crescendos.

What this says is, unless you know how to convert Art-Echo rolls to
Ampico, there is no sense cutting them.  Below is a tubing chart to
know how the Ampico trackerbar corresponds to the same hole of an
Art-Echo:

Art-Echo........Ampico

BASS:
Int. 1..........0 Ampl.
Int. 2..........X
Int. 3..........tb #2
B Int. cancel...tb. #4
B diminuendo....Shut off
B. cresc........tb #6
hammer rail.....cancel (#7)

TREBLE:
can B8, T6, T8, also RR.....reroll
hammer rail.....cancel (#7)
pianissimo*.....tb #6
T. crescendo....fast cresc. #5
T. diminuendo...tb #4
T. int. cancel..soft ped.
Int. 3..........tb #2
Int. 2..........slow cresc #1
Int. 1..........sub. int.  (pianissimo*)

Since #1 and #5 in an Ampico operate together for fast crescendo, you
can see right there that something very basic has to be changed in the
Art-Echo first, to play Ampico rolls, or you'd be turning on Int. #2.
and T. crescendo together each time.  And what are labeled T7, T8, and
B8 are canceled by T9, and must cancel together, bass and treble.

So the sub-intensity and the bass and treble hammer rails actually
cancel together this way.  On the Ampico, the soft pedal is a
continuous slot.  The Art-Echo uses a L/C arrangement instead.

The conversion is a real success.  I was amazed at how well the Art
Echo performed Ampico rolls, once these changes were in place and
"tweaked." The main thing was adjusting the springs I had added to
give me the exact Ampico crescendo speed.  And, it proved one thing
about the Ampico -- the so-called "dual" crescendos operate as one
crescendo, and create the crescendo by operating the amplifier in
the pump.

Craig Brougher