SECTION 2: PREPARING THE SHAY FOR SOUND INSTALLATION
When you remove the coal tender, you will find a small printed circuit board (PCB) attached
with a phillips screw at about the center inside the tender. This small board is not needed for our
BIG SOUND™ system. We offer instructions for removing this unnecessary connector board
and installing the wires for power and for cylinder chuffing directly into the BIG SOUND.™ It is
possible to use our system without removing the small PCB, but the timing of the start-up will not
be accurate and the start-up and stopping sounds will be cut short. Between start-up and
stopping, however, the Shay sound will work as expected. We believe you will be happier with
the performance of your Shay sound if you remove the connector board.
Here is a sketch of the connector board. The four input power wires (usually red and/or black
but possibly another color) are wired in pairs into one side of the connector board. In the middle
section of the board are four diodes that reduce the flow of current before it reaches the white
connector on the opposite side of the board. From the white connector, the current is intended
to travel to the sound board via a pair of wires (usually one red, one black). Just below the four
power wires are two black wires that lead to the cylinders. These black wires flow through the
connector board and pass to a second white connector just opposite. Two yellow wires lead
away from the connector board and are meant to be installed into the sound board.
Unfortunately, it is the four diodes—which reduce the voltage to the engine-sound system—
that cause the truncated start-up and stopping sounds and affect the timing of the start-up. We
offer instructions for eliminating the connector PCB completely and instructions to modify the
PCB so it does not interfere with your sound output. Choose one or the other; neither method
is difficult, but it takes a little time. Remember, you can leave the connector PCB "as is," but the
sound sequence will be affected.
CON2
CON1
G 8 1 1 X - P C B 0 2
D1
D2
D3
D4
DIRECTLY TO CYLINDERS
CYLINDER CONNECTOR
WIRES (YELLOW)
DIRECTLY TO INPUT POWER
C
P
SPECTRUM™ SHAY CONNECTOR BOARD
INPUT POWER
CONNECTOR WIRES
(USUALLY RED AND BLACK)
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