[ Spencer Chase wrote in 050208 MMDigest:


>> Greetings,  Robbie's comment [in 050207 MMDigest, Duo-Art Operating
>> Pressure] suggests that I have a problem with heating of the power
>> supply or the magnet valves in my E-Roll Player system.  The opposite
>> is true.  I said that it is difficult to design a system that does
>> not overheat, not that I haven't done it.  I can play against Duo-Art
>> pressures indefinitely, without a fan or even much free air moving
>> over the valves and they never overheat.


What I recall reading here over the years is that the PowerRoll
system suffered overheating, and its engineer is still working to
correct the problem.  Nobody has ever reported such a problem with
the Gerety-Chase system, that I've seen in the MMD.

The PowerRoll has to cram all 98-odd magnets into the assembly that
clamps onto the tracker bar inside the spool box.  The Gerety-Chase
valve blocks, while quite compact, come in groups of 16 notes and can
be spread out over the width of the player action stack.

Readers shouldn't confuse the two systems.

Mike Knudsen