In Digest 99.06.08 -0000 Ken Slow wrote:

> The concept of controlling the organ from the MIDI source by teeing
> into the keyframe tubing is not straightforward.

Depends upon what is being teed into the keyframe!

> To control the organ by teeing into the keyframe tubing would therefore
> entail blocking off the keyframe side to prevent this venting the
> tubing to air. It would be then possible to control the organ's
> functions by introducing pressurized air via a relayed-controlled air
> valve that is connected and controlled from the MIDI output.  This
> still has not given any means to vent the system after the note (or
> whatever) has finished operating and it starts getting complicated to
> devise a 2-way changeover air valve that performs the keyframe
> functions.

Could this not be done by the normal pipe-organ type Primaries?
Essentially, they are set up as "two-way valves"; alternately
introducing  chest pressure, or atmosphere, into the Primary channel.
This is controlled by a pouch which is activated by a normal Organ
magnet; readily electrically "interfaced" with a MIDI device.

If necessary, perhaps a second Primary could be used for the original
mechanism as an expedient.

It would be necessary for me to look at a tubing diagram or schematic of
the instrument in question, but I'm pretty sure this could be readily
worked out.

Faithfully,

Richard Schneider, President
SCHNEIDER PIPE ORGANS, Inc.
Organbuilders
41-43 Johnston Street
Post Office Box 137
Kenney, IL   61749-0137
(217) 944-2454 VOX
(217) 944-2527 FAX
mailto:arpncorn@davesworld.net.geentroep   EMAIL (Note change in ISP's Domain-Name!)