[ Mike Walter wrote in 110627 MMDigest:

> The later Recordo systems did accommodate more possible combinations
> than the earlier system, but if you examine a roll or two, you will
> find a couple of things that are apparent.
>
> Almost all of the time there is one dominant expression hole
> perforated.  There are seldom two expression holes perforated for
> more than, let's say, three punches.  These short expression holes
> are to provide a very brief emphasis on a note or two.

Exactly.  This is even true for rolls numbered higher than 612720,
which are supposed to be for the later 16-step ("C") Recordo (per
the article "What is Recordo" by Bob Billings and Durrell Armstrong
in the old PPCo catalog).  This being the case, what is the point of
having a 16-step system if rolls are never perforated to take advantage
of this?   Perhaps my serial number information is incorrect.

> ... a small grand it was probably built to fit in a small apartment
> where a great volume of music was not needed or desired and was
> probably used as background music.

Yes.  I suspect that it was not designed to make full use of the
expression potential (unless it could use some sort of elusive 16-step
roll, which doesn't seem to exist).

> I would suggest that Craig hook up his vacuum gauge at the stack once
> more to determine if the system is providing it full potential.  By
> placing the tempo at zero and masking tape over the entire tracker
> bar, record the vacuum levels at: no intensity hole open; #1 hole
> open; #2 hole open; #3 hole open; #4 hole open; bass hammer rail
> open; treble hammer rail open."

This is what I did.  This how I determined that the expression had what
I called an "additive" effect, meaning that it is capable of 16 steps.

 [ Bob Billings wrote in 000518 MMDigest:

> If one is not familiar with the various Recordo mechanisms, the only
> way to tell for sure is to measure the stack vacuum while opening the
> expression ports.  If the vacuum increases when a high level port is
> open and a lower level one is then opened, it is a 16-step ("C").

Not necessarily.  Based on this test mine is a 16-step system.  But the
manufacturer may have not cared how the system responded to roll coding
that did not exist.

Another reason I think it was intended to be 5-step: In the drawer
there are four buttons, marked "P", "MF", "F" and "FF", which are teed
to the respective intensity port on the tracker bar.  This suggest 5
levels.  There were so many Recordo systems manufactured.  The quality
can vary.

In this case, it is a Vollmer piano with an H.C. Bay Recordo action.
Contrary to the reputation of H.C. Bay, the action is of very good
quality for a Recordo.

Nevertheless, I am making some changes that are minimally invasive to
the original system.  The main change is a cutoff pouch that bypasses
the expression system when the highest intensity is called for.  This
should achieve an effect similar to a Duo-Art crash valve.

So, the question is mainly academic at this point.  Where are the
rolls with multiple expression perforations that actually make use of
a 16-step system?  Perhaps they were only issued by a specific piano
manufacturer, like Schulz for the Aria Divina.  It would be interesting
to find out.

Craig Roothoff
Escondido, Calif.

 [ The 16-step system in the Duo-Art was patented by Aeolian.  Maybe they
 [ told the firms who made the Recordo action and rolls they should stick
 [ to the 5-level system or face a lawsuit for patent infringement.
 [ -- Editor (Robbie)