Good News on Expression Pedal Controls & Console Coversion Update

[JayR]

I have continued to work on the Kilgen Opus 7722 console conversion for my Church organist since last I posted. The conversion process is close to being complete and the console is mostly playable. The biggest setbacks have been working through wiring anomalies, which can be expected on a 55-year-old instrument.

One of the challenges I faced with this console was to apply my expression control circuit to multiple expression pedals - Great/Chior & Swell. In addition, the organist asked that I take one of the existing on/off switches on the console (Audtorium Expression) and change its functionality to separate the Great from the Great/Choir expression pedal at will. I am happy to say that all is functioning perfectly with the expression pedals!!!

I am reposting my expression control schematic and PCB patterns for any of you who may be interested in doing your own pipe organ console conversion. The advantage to using this circuit is you don't have to add a potentiometer and cam assembly to the expression pedals. This circuit works with the existing expression pedal wiring and spring contacts.

[ggoode.sa]

Hi Jay,

Thanks for the update on this project, and new pdfs for the expression array

I'm glad that everything is working as you needed it to. That is always very satisfying.

All the best,
GrahamG

[JayR]

Just to give you all a better idea of what the inside of an expression pedal looks like, I am attaching a picture of the contacts for one of the expression pedals I am working on. I am also attaching a picture of the two expression volume control circuit boards I made.

If you think about it, this console is 55 years old. The expression pedal assemblies are still very functional and have many years of life left in them. By using these circuit boards instead of a potentiometer and cam assembly, I should not have to change any parts in the near future.

Thanks for reading...
Jay