B234rB Page 2
6 5 43
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6 5 43
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Installation Instructions:
EMG Model: B234rB Stacked Volume or Volume/Tone (25K)
The B234rB has two controls that can be configured as two volume controls
or as a volume/ tone combination. Only the “B” Bottom Control can be used
as a tone control. The PC Board is marked with a “B” for the Bottom control
(larger outside control shaft) and “T” for the Top Control with the smaller, inner shaft.
The controls can be daisy-chained to produce a single output.
Both controls are 25K Ohm (Audio Taper) and are designed to work with EMG Active Pickups,
The diagrams included assume you have two pickups installed in your instrument.
Diagram #1
If you are using the two controls as volume controls the pickup inputs should be connected
to the “wiper” contacts of the pots, the middle two contacts.
Using the Wipers as the inputs will allow the controls to work independently of one another.
As shown in the diagram the output of each control comes from pins 5 and 6 on the left side
of each 6 pin header, they can also come from pins 1 and 2 which ever pair is more convenient.
Pins 1 and 2 are the same as pins 5 and 6.
Diagram #2
To use the Top control as a Volume and the Bottom control as a Tone Control simply install the
blue shunt onto the terminals as shown to the right. A capacitor has been pre-installed on the
circuit board. Once the shunt is in place it won’t be necessary to plug any
contacts onto the “B” 6 pin header. The shunt does all the work.
Assuming there are two pickups in your instrument, when you use
either tone control, both pickups will be effected. This is common
with passive style controls.
Pickup Inputs (Pins 3 & 4)
Top and Bottom
Pickup Outputs (Pins 5 & 6)
or (Pins 1 & 2))
Top and Bottom
Pickup Input
Pickup Output
- 9V +
BRIDGE PICKUP
OUTPUT
T
R
S
OUTPUT CABLE
TONE
BATTERY
BUSS
TONE
B124rH
NECK PICKUP
- 9V +
BRIDGE PICKUP
OUTPUT
T
R
S
OUTPUT CABLE
BATTERY
BUSS
NECK PICKUP
(T) TOP CONTROL
NECK PICKUP VOLUME
(B) BOTTOM CONTROL
BRIDGE PICKUP VOLUME
LOOPED CABLE
BOTTOM TO TOP
Diagram #4
Stacked Volume / Volume
Master Tone
Diagram #3
Daisy Chained
Volume Tone / Volume Tone
Diagram #1
Diagram #2
