Since no one else has replied to Harald Mueller's quest for info on
MIDI-fying a small paper roll organ I thought I would send in a few
words.

I have converters from both JW Electronics (John Wale) and from Octet
Design.  Both units work faultlessly and seem to be very well built.
For the conversion that Harald wants to do (less than 32 notes) I would
suggest the unit from J Wales.  It is smaller, a lot cheaper, and has
integral screw terminals for easy connection to the solenoids.  John
is also very helpful with all his tech support if it should be needed.

For the solenoids to let air into the trackerbar tubing I would suggest
the use of Peterson organ valves.  They are cheap, easy to mount and,
although they are not the smallest valves available, they have a long
history of reliability.

Phil Dayson