2018-5-24 Allen Organ Products - Church Organs, Studio Organs, Theatre Organs and MIDI products. Allen organs provide lavish styling and rich sound. Baldwin Studio Ii Organ Manual Midi Libre. 9934 Francis Bacon - Retrato de Una Pesadilla 796 Starlight Lounge (Import). Posts about MIDI on Analog Organ written by RVB. The Baldwin Cinema II has numerous wire contacts per key. When a key is pressed, it lifts a jack (much like a harpsichord jack), bending various wires and forcing them to touch contacts. The Baldwin Cinema II has numerous wire contacts per key. When a key is pressed, it lifts a jack (much like a harpsichord jack), bending various wires and forcing them to touch contacts. According to the service manual, the stop sounds are controlled by small gold wires being pushed against elastomer contacts, while the rhythm sounds are controlled by a wire touching a silver rail. The reason for the difference is apparently that the stop sounds, controlled by shorting a field-effect transistor, are susceptible to a “pop” unless the contact is made with gradually decreasing resistance. The rhythm sounds are not triggered in the same way and can rely upon a basic on/off contact. The elastomer technology is intriguing, and I imagine that there is potential for using the arrangement to control velocity MIDI inputs much like piano controls operate. This would be useful if I were building a piano, but I’m building an organ. The simple on/off signalling is sufficient, and, as it turns out, much easier to connect. I lifted up the lid and took a look at the upper keyboard: A closer view of the top of the upper keys on the treble end: And here is an out of focus photo showing the contact wires, jacks, the silver rail and the elastomers: After poking around with test probes, I found what I was looking for: a simple on/off contact when a key is depressed. Most of the wires coming from the contact assembly had bias resistance–something I didn’t want to go to the MIDI controller I would be building. But, providentially, the upper contact before the limiting diode (shown below) showed a direct connection when a key was pressed. The black lead above is connected to an uninsulated jump wire that connects to ground. The entire metal key frame is grounded. The red lead is connected to a diode lead. If I connect to the other side of the diode, resistance is 3K ohms. The wires from the diodes are color coded and arranged by octave. They control the existing circuitry that allows sounds from the tone generators. I would like to keep the wires because they are so orderly. Each color represents a note. For instance, C is black, and it is a fairly easy thing to keep track of each key’s wire. The problem is that the diode presents resistance and a one-way current limit that I don’t want. I’ve seen other organ MIDIfiers simply tear out all the wires and start over with new wiring, but I couldn’t bring myself to waste the beautiful color-coded arrangement. So my proposed solution is simply to solder a jump wire past each diode and use the existing key wires to connect to the MIDI hardware.
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