A Virtual Organ for Our Saviour
And an Homage to the Rodgers 32-B
By Rob Hart
Starting in the summer of 2021, music director Casey Hannan and I have taken small steps in the process of making a virtual pipe organ available at Church of Our Saviour. The organ sounds that we have heard recently during worship all come from prototypes of that instrument. At the end of 2024, we took bigger steps, rewiring two keyboards, purchasing a capable computer, and obtaining larger, more versatile sound sample sets.
The Rodgers 32-B electronic organ that has served us for 60 years has come to the end of its life. With three keyboards and a pedalboard, this organ imitated the sounds of a traditional pipe organ and allowed us to accompany worship in a very economical fashion. In November, Casey and I began to disassemble the electronics inside the console of the old organ in order to install electronics and a computer for the future organ. I have always thought of the Rodgers organ as a marvel of postwar electronic technology, and in the process of taking it apart, my appreciation has grown. I can now imagine the skillful work required to design and assemble this instrument. Each of thousands of components was soldered by hand to one of many copper-clad circuit boards. Sounds originated in oscillator circuits, and wires carried the signals (61 for each keyboard) from one board to the next for filtering and mixing. The boards and wires filled three large wood racks in the console. It is clear that the assembly of the electronics required considerable skill and was done with care and attention to materials, so that the organ would play every note correctly, and continue doing so for 60 years.
Figure 1: Racks of electronics inside the console of the Rodgers 32-B.
The first figure above shows the three racks of electronics in the console. Each rack could pivot on the hinges on the left side to allow access to all the circuits. There are about 100 small gray cylinders on the boards of the center rack in the picture. Each of them is a part of the oscillator circuit for a particular note. When a note was played on the organ, a signal energized the oscillator circuit. The waveform that it produced was filtered and altered by other circuit boards in a way that was dictated by the stop tabs that the organist actuated. In order to tune the organ (infrequently), each of these cylinders was turned to adjust the pitch.
Figure 2:
One of the circuit boards from the 32-B console, showing wire bundles.
The second figure shows one of the large circuit boards that was probably part of the filtering mechanism. In it, you can see the individual soldered components and the wire bundles that carry signals to faraway boards. The bundle of slightly larger wires in the center carries electrical current to provide power to other parts of the organ. The colors of the wires identified sets of signals, and their visual effect is striking. The innards of the 32-B remind me of an organism, having analogs of nerves, vessels, and muscles. The analogies do not go very far, but the electronic design is complex, and the impression remains of an organic thing.
Figure 3: Wires from one of the keyboards are attached to new circuit boards.
Once the electronics were moved out, it was simple to remove and investigate the keyboards. They are built well, and it seemed worthwhile for us to modify them for use in the virtual organ, at least temporarily. We have rewired two of three keyboards. In the photo below, we show the 61 wires from the upper (Swell) keyboard soldered to a circuit board. The yellow wires are from the original organ, as are the 61 tiny, red-colored components (diodes) soldered onto the board. The key signals are routed to the green microcontroller on the right, which communicates directly to the computer. At the bottom of the picture is the bundle of wires for the middle (Great) keyboard, for which we kept much of the original wire and circuit board.
In early 2025, we will complete the wiring of the original organ pedals and the lowest keyboard (Choir) to incorporate in the console with the new computer. This will make the virtual organ playable at the old console. While this should be functional for our worship, there is more to be done. We will continue to update in the newsletter as we work further with the keyboards, improve the sound system, and make a friendly user interface.
As we learned more about the Rodgers 32-B, we were motivated to keep as many as possible of the components of the original console. This is partly a result of our growing respect for the 32-B as an instrument in its own right. It is interesting for me to think about how the making of the old and new electronic organs is related to pipe organ tradition. In what ways was the Rodgers organ a continuation of older craft? Are the new virtual organs bringing us back closer to traditional instruments, or leading in another direction entirely?