The Wurlitzer console is called a 4 manual which defines it as having 4 keyboards. Each keyboard is named in Wurlitzer design standards - Accompaniment, Great, Bombarde, and Solo. Number of keys equals 61 for each manual and that represents 5 octaves of notes.
The bottom two manuals (Acc & Grt) are identified as keyboards with Second Touch. That means the player can press the keys with regular weight to engage the First Touch which would then play stops called for at that command. But the player can also press the keys with additional weight, and the keys go down further which would then engage the Second Touch to play additional stops called for at that additional command.
As is common with 2nd Touch consoles, only the bottom 2 of 4 keyboards need 2nd Touch. This is useful in many ways including counter-melodies now playable and hearable from different stops assigned for the 2nd touch of the keys playing the counter-melody. In other words, while the left hand is playing chords in harmony with the right hand playing melody, the 2nd touch can be employed with brighter stops and as the LH is playing a chord for harmony, it can also play a counter-melody with one of its fingers pressing harder to the key that is engaging the 2nd touch for counter melody.
From the pictures below, you will notice this console is made from standard Wurlitzer mahogany wood with raised panels in the sides and rear of the console. This style is known as the Fox Special.
Stop tabs control the ranks of pipes that can be played on each manual and the pedals. There are nearly 300 stops calling for sound from approximately 3600 pipes and percussion instruments. The stops are clearly engraved and use a standard Wurlitzer font. Colors of stop tabs represent different ranks of pipes and these colors are common on all Wurlitzer consoles.
Mechanics of every stop are designed and built using nearly 40 different parts and wire connections. These parts are hidden on the back side of the stop tab. Four wires are connected to each stop. With 300 stops and 40 parts in each, there exist over 10,000 items just to make the stops work in this console. Electro-magnets are used to automatically press the stop down to engage it, and press it back up to disengage it. Two electro-magnets for each stop totals 600 magnets that are powered by a 50-volt power supply. And 4 wires connect to each stop. That connection, and the other end of that wiring which connects to the controller cards, totals more than 2000 wiring connections. Each one matters! Each one must be correctly connected for everything to work properly when somebody is sitting at the console to play.
Wurlitzer organs were designed and built more than 100 years ago. Electric magnets do much of the work to make a pipe organ play and 12-volts DC power is used to control the magnets. Console keys send 12-volts of power to a controller that determines which stops are selected at the console to play. And the controller then lets the 12-volts go from the controller to the correct pipes to play.
Original manufacture of theater organs used a DC generator to create the necessary power to run the organ. This generator was incorporated in the design of the wind turbine motor. When the blower was turned on, the generator automatically began spinning from blower power and created electrical current from the console which fired magnets at each pipe. The generator for the Clark Music Foundation Wurlitzer has been replaced by multiple power supplies that send 12-volts through the chambers to pipe and percussive instrument notes and other necessary parts that make things happen when the organ is played. It was 1980 when we got our first pipe organ and we used the generator as part of the wind turbine. When big chords were played with many ranks called for, console lights would dim! Yeah, that's because the wind turbine was slowed... kind of lugged down for such a call of wind. This would slow the generator spin and decrease the current output dimming the lights and flashing them. It was never a problem... just a kind of fun that has now been lost with newer power supplies that don't sag the power.
A company known as Spencer Orgoblo made most of the blowers for many different American pipe organ companies. It still exists. The Clark Music Foundation Wurlitzer uses a large blower to create the necessary wind to operate the pipes, percussions, sound effects, and nearly a half ton of weight in the Swell Shades that open and close to manage volume to the listener. The blower is 52-inches in diameter and has 2 turbines sitting on a 2-1/4 inch diameter motor shaft that is 40-inches long. Air is drawn in from the center on the back side of the blower. It increases in pressure as it passes from one turbine to the next. Then it exists under full pressure at the front and top of the blower can. The pipe that carries static wind from the blower is 16-inches in diameter and directs the air to an 8-foot box lined with material to somewhat quite the airflow. Wind exits the box to a 12-inch pipe that runs 50-feet through the chambers.
Many people are interested in the pressure of the wind and surprised to learn that it is only about 1psi. Everything is so big including the electric motor at 20hp. But a pipe organ doesn’t run on high pressure. Considering the smaller pipes of the organ, high psi would so easily damage the thin metal used to create the “whistle” of the pipe. Pressure is lower than shop tools. What is required for a large pipe organ is a tremendous amount of wind- a high volume of air. More than an adequate amount of air must be supplied to guarantee the pipes will always play at their designed pitch. When the air volume sags, the pitch sags.
The smallest pipes are the size of a pencil and require very little air. But the larger the pipe, the more air it requires. An example is the biggest pipes in the organ which are 16-feet long and 10-inches in diameter. Though you can blow air from your mouth and easily make a small pipe create tone, it’s impossible to blow enough air in a large pipe to create sound. And considering an organ with 3000 pipes in all sizes, much air is required from the blower to make it play with consistent pitch. Not all 3000 are played at once but in a full-organ sound, more than 100 pipes could be begging for wind.