Mechanical Pipe Organ?

[myorgan]

Folks,

I just had the opportunity to play a mechanical organ by Zimmer. I looked inside and certainly saw the tracker mechanism, however, when I pulled any of the couplers (Sw>Pd, Gt>Pd, Sw>Gt), the stops coupled, but no keys from the coupled manual moved.

I thought a mechanical/tracker organ meant everything is actually mechanically coupled? Is there some means of coupling ranks without the coupled manuals showing it mechanically? I don't think I've ever seen that before.

Thanks in advance for any clarification you can all provide.

Michael

[minibutmany]

I know nothing about pump organs, but I have played a tracker organ that doesn't actually move the keys when the coupler is engaged. Despite this you can still feel a difference in touch when you play a key that has already been played from a different keyboard. Usually coupler action attaches or contacts some part of the key body, but in this case it bypasses the keyboard and just triggers the pulldown wire directly. I drew a really crude picture to show how I think this works.
This would act as a great to swell coupler.

[myorgan]

I drew a really crude picture to show how I think this works.
This would act as a great to swell coupler.

Thank you so much for the drawing. I suspected it was something like that, but wanted to be sure before I provided my "review" of the organ to my former organ professor. I've always played tracker/mechanical instruments that affected the keys of the coupled keyboard rather than one that only engages the tracker itself.

You've been a big help.

Michael

[VaPipeorgantuner]

It depends on the mechanical design of the coupler action used in a particular organ. I have serviced mechanical-action organs where the coupled manual keys do not react. Sometimes this is done with weights at the tail of the keys.

Rick in VA

[myorgan]

It depends on the mechanical design of the coupler action used in a particular organ. I have serviced mechanical-action organs where the coupled manual keys do not react. Sometimes this is done with weights at the tail of the keys.

Rick,

I understood Mini's post, but am missing how weights at the tails of the keys would work. Are they just shifted from front to back? Are they on the original manual's tracker wire and stopped by a ferrule unless the coupler is pulled to add them to the coupled keyboard? I appreciate the post, but it does leave me confused.

In fact, you may know the organ. I'll list it for you privately.

Michael

[jbird604]

Michael, it's also possible that the coupling in that organ is done electrically, even though the primary action is purely mechanical. I understand that this is quite common with some builders.

The home division of each manual is directly linked to the keys with the tracker wires, etc., but each chest is also equipped with a set of electric valves. The electric valves open an air inlet into each key channel in much the same way the tracker part does, so the coupled division plays almost exactly as it would if it were mechanically coupled. But the player doesn't have to exert the extra force that would be required to open two or more mechanical valves with each key.

The mechanical portion of the instrument is thus simplified, the inherent advantages of tracker action are retained, as far as the player can tell, but the electric valves take over some of the work. Playing one of these you wouldn't be aware of the electric couplers, because you are still feeling the genuine tracker action on all keyboards.

This is NOT the same thing as "direct electric" action (a la Wicks) in which an electric valve is placed at the foot of each pipe, one valve per PIPE. With electric coupling of tracker organs, the electric valve is placed next to the corresponding mechanical valve in each KEY channel, one valve per KEY, so as to mimic the attack and speech-affecting characteristics of the mechanical action. Of course, the player forfeits the ability to subtly manipulate the valve with different types of touch on the coupled divisions, but of course retains that control on the home division of each manual. I'm guessing almost nobody can spot under normal playing conditions.

I'm sure purists do not like this, but it is one way to do it.

[myorgan]

Well, here are the photos of the organ. A nice little Baroque practice instrument.

Really, the organ wasn't laying on its side, but I hope to rotate and get the photos re-uploaded. I thought about getting photos of the action, but didn't think I needed to--then I found out about the coupling action as I had to leave. Oh, well. Better luck next time.

Michael

P.S. Some have asked about raising or lowering the bench height. Note the chocks on either side of the bench and various designs.