Many thanks to all those who have given advice, both privately and
in the MMD, on my solenoid and driver burnout problem.

For the record, I have decided to go with the MIDI-operated timer
switch designed by Spencer Chase.  For details see the MMD Archives
2001.05.25.  I think it will eliminate most of my concerns.

I have no concern about the solenoids burning out during regular
playing; they can stay on at full voltage for 10 to 20 minutes without
a problem.  It is only if the MIDI board causes a hang up and I do not
notice it that there might be a difficulty -- a solenoid could stay on
for days!

As an extra precaution I will segmentize the "return" lines of the
driver boards into two or four groups and fuse each group at the
5- or 6-amp level.

Again thanks to everyone for their help and to Robbie and Jody for
making it all possible.

Phil Dayson
Vancouver Canada