Craig Brougher seems to be very knowledgeable about the player pianos,
where I have very little or close to none.  So it would be foolish to,
and I am definitely not, argue against any points he makes.  But I'd
like to make a few comments.

Craig's suggestion about me stating that "new is better than the old"
is partially true, but not in the sense that "old is bad, new is good".

Anything that has been made with craftsmanship and care is "good", no
matter when it was done.  The people making the player piano systems
100 years ago where probably geniuses, ahead of their time.  They did
things no one else thought about before.  They wanted the best they
could get, and went for it.

In a technical matter, there is no doubt in my mind that, if those
people would still be alive and working today, they would use computers
and electronics to the max.  Not one hose would be found in their
instruments.  And those instruments would play better for it.

This, however, doesn't mean that what they made before is bad.  It's
just an ongoing process, which gets harder all the time as the gap
between what we have and perfection is getting smaller.

Craig may be right if he states that the work of the new designers is
(1) not up to the standard it should be, but not expensive, or (2)
to the standard it should be, but too expensive.  I cannot confirm or
deny any of that.  But Craig seems to agree that a new system can be
better if the design was well done.  I'm with him on this one.

He also has a point about the problems with solenoids.  Theoretically,
a solenoid coil would be an incredible device, except that the problem
of resistance is showing up again.  If one could have super-conducting
wires, wires that transport electricity without any resistance, that
would be some solenoid!  But life ain't that simple.

Because of the resistance, a part of the energy is not converted
into magnetic force, but into heat.  And if the coil heats up, the
resistance increases (another nasty law of nature).  So to keep the
same magnetic force, one must increase the input power, with more heat
as a result.  This will end in a coil burnout if you are not careful.

For this reason, manufacturers of coils will provide you with a chart
stating the amount of time a coil can have a certain current before it
gets too hot.  If you need a coil that must be kept under power for long
periods of time, like one day, you need a coil rated for 100% duty.
This means that the coil can be kept under power for all that time,
without heating up above an acceptable level.

It's the task of a designer to make the proper calculations so that
coil burnout will not happen.  In the case of a piano, you can reduce
the size of a solenoid because it's only the attack of the note that
needs much strength, not the holding down of the key.  So if 25% of the
power is enough to hold the key down, you could use a 33% duty coil:
give it 100% power for the attack duration (say 50 ms) and drop to the
25% holding power.  This way you reduce the hardware size by 66%.

If the engineers of Yamaha and the like did not do their homework on
this matter, shame on them.  But it is hard for me to believe that
these guys were born yesterday.

Regards,

Tony Decap
Tony & Frank Decap, DECAP Herentals, Belgium
http://www.decap-herentals.be/

 [ Many of the important patents for duty cycle control of the
 [ solenoids in player pianos are held not by Yamaha but by Wayne
 [ Stahnke and by Kirk Burgett (PianoDisc).  Most of these patents
 [ were granted in the mid 1970s and so they expire within the
 [ next few years.  (The solenoid piano is older than we realize!)
 [ -- Robbie