I now have an add-on contact strip.
Well, No one ever mentioned anything about add-on contacts for older analog organs (like a Conn 651) so I did it. I bought some orchestra bells and needed to add them in. I also wanted to add MIDI and other options so I did not want to use the original mechanical contact strip. So I did it - designed an electronic contact strip with a 4 layer PC board and HALL effect magnetic switches.
Today I installed my first 37 note contact strip to operate the orchestra bells (it can be extended to 61 notes). Along with it is a separate driver board for the orchestra bells - which drives 2 contact strips plus has MIDI input AND a midi output. Contact strip and MIDI can be used at the same time, or just contact strip or MIDI input. It has inputs for stop tabs - so for the 651 I disconnected the 1' Fife from the generals and connected it to the bells. The Fife still operates from the pistons as the fife contact is disconnected only from the non-piston state and will operate the bells with the pistons - and the #5 piston will still turn on the fife. (The 1' fife is pretty useless, a tierce would have been better and offered more tonal color. Why did Conn do that? At least the 651 doesn't have the couplers on the great and solo manuals like the 650 and 652).
Where the 651 is located - Merril Gardens in West Seattle, is a retirement building for independent living. As you may have seen, Seattle has been hit with really bad ice & show this week so today was my time to install it. It only took about 30 minutes to put it in and adjust each contact. I have an LCD display to show each contact, so you can adjust any contact without having the bells power on. The display can slao show all MIDI input data so you know what is gong on in the MIDI area. Tomorrow is a Christmas special dinner with carrolers and organ music, so I HAD to get the bells installed. I'll clean up and fine tune the contacts next week and then post some photos of the installed contact strip.
I have probably an hour or two to get everything cleanly installed inside the console and the power for the new stuff connected into the power switch of the 651. That will come later. It HAD to work for tomorrow's special dinner. Fortunately, the driver board is hanging out the back so no one will see it. I'll have to make a shelf for the top of the console. I had 2 sets of small 144 Conn pipes on top and with the orchestra bells, there isn't space. I'll build a shelf for the pipes that raises the pipes up and over the bells. (FYI: I have found so far 3 different types of orchestra bells from the 70's for electronic organs.)
The magnetic contact strip should be able to be installed anywhere. In the Conn, the back part of the keys is steel so the magnets just stick on. For wood keys, you can glue the magnets or get ones with a hole and screw them on or use a small brad if the hole is small. The driver board also can rerceive Z-Tronics or be programmed for just about anything. It also has delayed turn-on of the traps power so things don't go BOING on power on or off.
Digital Pipes
http://pstos.org/instruments/wa/seattle/lajko.htm