I know that there have been a number of magnet valves designed to play
pneumatic player systems over the years, the latest of course being the
PowerRoll system.  But to my mind, they all have had some drawbacks.

For instance, a tiny unit small enough to put in-line with trackerbar
tubing would probably not be an answer to a reproducer or player
requiring vacuum pressures changing from 5" or less, all the way to
beyond 100."  And a tiny valve like that would constrict the airflow
to a pneumatic valve at low tension to the degree that performance at
those levels would be non-existent.  All this regardless of reliability,
which definitely would become a problem with an inline unit covered
with rubber, and required to open and close rapidly under high tension.

For low pressures and short tubing runs in a hurdy-gurdy, I'd say they
are probably okay.  That might work out, if they are reliable.  I keep
harping on reliability, as I had returned my PowerRoll to Larry
Broadmoore four times, and at this last writing I haven't gotten it
back again.  That was over a year ago, October of 2000.  Its problem
seems to now be the glue that allows the magnets to slide around when
they get warm, but there may be other factors I am not aware of.

Most serious pneumatically played instruments require some very
exacting design work in the magnet efficiency, size, and structure in
order to play reliably over the years.  Reliability, let us not forget,
is the differential underlying quality of a fully restored pneumatic
system, versus the electric pianos.  The hybrid electric MIDI to
pneumatic player (depending on the software provided) can conceivably
become the best all-around player system there is for a continuous
stream of live music, hands down.  But it has to be easy to use-- so
that a child can do it.  (None of them yet provide the opportunity to
share in its fun by watching or singing the words as they go by).

What I have noticed is the typically squirrelly, trouble-prone, crashy
software one has to use, and sometimes the goofy MIDI interface designs
that are half-thought out and then thrown together and sold-- forever,
it seems.  Reminds me of the trouble light.  Ever since that thing was
invented it has never worked right, but each time they change the color
of the cord, they have them hanging at the checkout stands and people
buy one.  Do they just collect them? Surely they don't expect to use
them!

So when Spencer Chase and Gene Gerety say they are researching these
things and want to come up with something that's done right the first
time, I think it's a good idea to bide our time, and then see what
they've accomplished.  If they've done what they hope to have done, it
will be the first time  that something really reliable has appeared
that will have the small size, the air and electric capacity to operate
all forms of pneumatic instruments regardless of the vacuum or positive
pressure differences.

The PowerRoll magnets get hot enough to malfunction on a good
reproducer.  I own an Ampico and it didn't play my piano for long.
So until I see something that is going to be better than that, I am
going to be cautious, but fair.  Now, I will not discount the fact that
Larry Broadmoore is still working on his invention and might improve
it.  I bought it with the understanding that if I purchased one when
I did, that I would get all the latest updates as they became
available.  We'll see.

I will vouch for Spencer Chase as being a real perfectionist with
patience, however.  He's a man after my own heart, and isn't going to
get in a hurry to put his ideas on the market, until he has done
everything he can think of to make it fail.  I rather suspect we are
going to see a full-flow valve that will operate at low voltages for
vacuum levels that would ordinarily stop most magnet valves.  For
instance, the Petersen 5/8" magnet valves are fine for pressures up to
7 inches, but 8 inches is a reach (they'll work with some spring
adjustments), and 10 inches is doubtful for all but the smaller pipes.
These magnets have to be well-designed, and just "uncorking a hole"
isn't all there is to it.

Craig Brougher