EMG JMASTER SET Service manual

INSTALLATION INFORMATION
EMG MODEL: JMASTER* SET
Warranty
All EMG Pickups and accessories are warranted for a period of two years. This warranty does not cover failure due to improper installation, abuse or damage. If
upon examination the pickup is determined to be defective, a replacement will be made. Warranty replacement products are covered by this same warranty. This
warranty covers only those pickups and accessories sold by authorized EMG Dealers. This warranty is not transferable.
© 2023 Copyright EMG INC. All Rights Reserved.
PO BOX 4394
SANTA ROSA, CA
95402 USA
P [phone]
F [phone]
EMGPICKUPS.COM
0230-0378rA
Installation notes:
The JMASTER* Set is an active pickup option for Jazzmaster** style guitars. The contents of this set allow for a basic control scheme consisting
of master volume, master tone, and a three-position toggle switch (not included). The unique upper horn controls (i.e. rhythm circuit) found on
many Jazzmaster style guitars will NOT be compatible with the EMG JMASTER Pickups, and should be removed or disconnected when installing
the JMASTER Set. If you’d like to add a robust active EQ section to your instrument, please consider the EMG JMASTER SYSTEM which is available
as a pre-loaded pickguard. The standalone JMASTER Set is intended for more basic setups and/or instruments which lack sufficient cavity space
for upper horn controls. Please verify that your instrument’s pickguard can accommodate the JMASTER Pickups before installation.
SPECIFICATIONS: MODEL:
JMASTER
Logo Color Gold
Magnet Type Alnico V
Resonant Frequency (kHz) 3.15
Output Voltage (String) 0.50
Output Voltage (Strum) 0.80
Output Noise (dBV) -120
Output Impedance (kΩ) 3.16
Current @9V (Microamps) 350
Battery Life (Hours)† 715
Maximum Supply (Volts DC) 27
†estimate for two pickups powered by a single 9V, 500mAh battery
.390
(10)
(6)
(8)
.235
.310
BATTERY
BUSS
2 PICKUP IN/ OUT
BATTERY BUSS (B245)
STEREO OUTPUT
JACK
1 VOLUME CONTROL (25K)
1 TONE CONTROL (25K) PICKUP CABLE 15” (38cm)
OUTPUT CABLE 6” (15cm)
2 CONNECT CABLES 5.5” (14cm)
BATTERY CABLE 7” (18cm)
- 9V +
PICKUP CABLE 11” (28cm)
Included with each set:
ADJUSTMENT SCREWS (x12)
**JAZZMASTER is a trademark of Fender Musical Instruments Corporation
1.625
(41.3)
1.800
(45.7)
.843
(21.4)
.40 TYP
3.625
(92.1)
1.610
(40.9)
R .187 TYP
(4.75)
*JMASTER is a registered trademark of EMG, Inc.

JMASTER SET INSTRUCTIONS Page 2
General Notes:
Every attempt has been made to make this a solderless installation.
There are some instances where this is not possible;
1) If your instrument uses a long panel output jack and you had passive pickups,
you will need a new stereo output jack. The Switchcraft 152B is recommended.
Soldering to the new jack will be required, refer to Diagram #6.
2) If your instrument has a battery holder installed, soldering may be required
to splice its wires to the EMG battery cable. Refer to Diagram #8.
3) Instruments with two pickups may need soldering to the selection
switch for some installations.
Installation (Two Pickup Guitars with Selection Switch):
Guitars with two pickups and a selection switch will use the EMG B245 Pickup Buss
as shown in Diagram #2. Find a place to mount the Buss in the control cavity before
starting. Then, after the cables are routed use the velcro to mount it securely.
Before restringing your guitar, it’s helpful to check the function of your pickups
and controls by performing a “tap test” while plugged into your amplifier set to a
low volume. Tap gently on the pickups with a small screwdriver to confirm your
pickups are working and that your wiring harness has been properly connected.
Direct mounting your pickups will require placing hard foam beneath each pickup.
Many instruments will already have foam underneath the stock pickups, but you
may also cut a piece from the packaging foam that comes with your EMG Pickups.
****Tips and Tricks**** Start your installation by:
****Tips and Tricks**** Start your installation by:
1) Determine which type output jack your instrument has.
1) Determine which type output jack your instrument has.
A Stereo 12B type is Included, but if you have a long panel jack
A Stereo 12B type is Included, but if you have a long panel jack
a SwitchCraft 152B Long Panel Jack will be required.
a SwitchCraft 152B Long Panel Jack will be required.
2) Remove the strings, remove any existing Pickups and controls
2) Remove the strings, remove any existing Pickups and controls
(remember the order and function of each control)
(remember the order and function of each control)
3) Determine a good spot for the Pickup Buss and make sure the
3) Determine a good spot for the Pickup Buss and make sure the
cable or wires from the selection switch will reach the Buss
cable or wires from the selection switch will reach the Buss
4) Install the EMG Volume and Tone Controls and tighten them in
4) Install the EMG Volume and Tone Controls and tighten them in
5) Then install the pickups keeping any excess cable under the pickup
5) Then install the pickups keeping any excess cable under the pickup
rather than in the control cavity.
rather than in the control cavity.
6) IMPORTANT: EMG Active pickups do not require a string ground wire!
6) IMPORTANT: EMG Active pickups do not require a string ground wire!
DO NOT reconnect the string ground, it is unnecessary and may pose
DO NOT reconnect the string ground, it is unnecessary and may pose
a shock hazard if using a vintage amplifier.
a shock hazard if using a vintage amplifier.
Diagram #1
Insert the plug onto the 3 pin header
of the pickup as shown above.
Note the orientation arrow.
Refer to Diagrams #1, #2, and #3
1) Install the pickups and and route the pickup cables to the control cavity.
If the cables are too long, wind up the excess and tuck it inside the cavity
2) Mount the Volume and Tone controls onto the body or pickguard.
Plug both pickup cables into the B245 Pickup Buss (BLACK Shroud) as shown.
Refer to diagram #2, Bridge Pickup to position 1 and Neck Pickup to position 2
3) Plug a connect cable from the Pickup Buss (position 3) to the Master Volume
control as shown in Diagram #3
4) Plug a connect cable from the Master Volume to the Master Tone as shown.
5) Strip the insulation from the switch wires and Insert them into the GREEN
Terminal Block and tighten the screws with a small screwdriver.
The Bridge pickup goes to the BR Terminal
The Neck pickup goes to the NK Terminal
The Output of the switch goes to the O Terminal
If there is a ground wire coming from the switch, insert it into one of the black
GND terminals on the block.
If using a solderless EMG 3-way toggle, refer to Diagram #5.
6) Plug the output cable onto the Master Tone control and connect the output
wires to the output jack by pushing the connectors on as shown.
WHITE wire onto the TIP (T) contact,
BLACK wire onto the SLEEVE (S) contact
BLACK Battery Negative wire onto the RING (R) contact.
7) Plug the RED wires of the pickups onto the V+ Buss (RED Shroud)
along with the RED wire of the battery clip.
Extra pins on the V+ Buss are for EMG Accessories.
8) Wrap the battery in a piece of insulating foam and place it securely in the
control cavity.
9) Before restringing your instrument, perform a “tap test” as described above
to check that your setup performs as expected.
2 Pickups / Toggle Select Switch / Master Volume and Tone
Diagram #3
2 Pickups
Toggle Style Select Switch
Master Volume & Master Tone
Diagram #2
BRIDGE PICKUP INPUT
NECK PICKUP INPUT
OUTPUT
NECK PICKUP
BRIDGE PICKUP
TO SELECTION SWITCH
PLUG IN
LIKE THIS!
OUTPUT TO
MASTER VOLUME
TONE
B124rH
VOLUME
B122rH
MASTER
TONE
BRIDGE PICKUP
NECK PICKUP
BATTERY
NEG (-)
MASTER
VOLUME
T
R
S
OUTPUT CABLE
RED
RED
RED
GROUND
BRIDGE P/U
NECK P/U
OUTPUT
- 9V +

JMASTER SET INSTRUCTIONS Page 3
TIP
RING
SLEEVE
Refer to Diagram #4
1) Install the pickups and route the pickup cables to the control cavity.
If the cables are too long, wind up the excess and keep it under the pickup.
2) Mount the Volume controls into the body or pickguard.
Plug both pickup cables onto the Volume controls as shown.
Plug a connect cable from the Bridge Volume control to the Pickup Buss (Position 1)
Plug a connect cable from the Neck Volume control to the Pickup Buss (Position 2)
3) Strip the insulation from the switch wires and insert them into the GREEN
Terminal Block and tighten the screws with a small screwdriver.
The Bridge Pickup goes to the BR Terminal
The Neck Pickup goes to the NK Terminal
The Output of the switch goes to the O Terminal
If there is a ground wire coming from the switch, insert it into one of the black
GND terminals on the block.
If using a solderless EMG 3-way toggle, refer to Diagram #5.
4) Plug the output into the the Pickup Buss (Position 3) and connect the wires
to the output jack by pushing the connectors on as shown.
WHITE wire onto the TIP (T) contact,
BLACK wire onto the SLEEVE (S) contact
BLACK Battery Negative wire onto the RING (R) contact.
5) Plug the RED Wires of the pickups onto the V+ Buss (RED Shroud)
along with the RED of the battery clip. Extra pins are for EMG Accessories.
6) Wrap the battery in a piece of insulating foam and place it securely in the
control cavity.
7) Before restringing your instrument, perform a “tap test” as previously
described to check that your setup performs as expected.
BATTERY
NEG (-)
RED to BATTERY BUSS
Soldering to the 152B Panel Jack:
If your instrument has a long barrel jack like the one below,
you will need to solder the output cable and battery clip as shown.
Ground (Black) to the Sleeve
Signal (White) to the Tip
Battery Negative (Black) to the Ring
2 Pickups / Toggle Select Switch / 2 Volumes (No Tone Control)
- 9V +
Diagram #4
2 Pickups
Toggle Style Switch
2 Volumes (Dependent)
Diagram #6
FROM TONE
OR VOLUME
Diagram #5
Connecting to the B289 3-Position Toggle:
Install the 4 pin Connector housing on the switch as shown
in the diagram below. Install both of the 2 pin connectors on
to the 4 pin connector between the black and red housings
as shown. The black and green terminal blocks will not be
used for the switch.
For more details, refer to the B289 Instructions.
NECK PICKUP
BRIDGE PICKUP
BATTERY
NEG (-)
RED
RED
RED
GROUND
BRIDGE P/U
NECK P/U
OUTPUT
- 9V +
T
R
S
OUTPUT CABLE
VOLUME
B122rH
VOLUME
B122rH
NK VOLUME
BR VOLUME
Note: This configuration utilizes a second 25K volume control that is not included in the JMASTER Set.
Additional solderless controls are available at emgpickups.com

JMASTER SET INSTRUCTIONS Page 4
Diagram #7
2 Pickups
Toggle Style Select Switch
Master Volume & Active Accessory
VOLUME
B122rH
BRIDGE PICKUP
NECK PICKUP
BATTERY
NEG (-)
MASTER
VOLUME
T
R
S
OUTPUT CABLE
RED
RED
RED
GROUND
BRIDGE P/U
NECK P/U
OUTPUT
If the instrument has a Battery Holder:
If your instrument has a 9 or 18 Volt battery holder you can still
use the EMG Connectors to supply power to the pickups.
Simply cut and strip the wires from the battery clip provided.
Twist the wires together and use the shrink tubing included
to cover the connections. Soldering the wires is the preferred.
9/18 VOLT
BATTERY
HOLDER
Cover these connections with the
shrink tubing provided.
BLACK to RING terminal
of the Output Jack
RED to BATTERY BUSS
Diagram #8
Refer to Diagram #7
1) Install the pickups and and route the pickup cables to the control cavity.
If the cables are too long, wind up the excess and tuck it inside the cavity
2) Mount the Volume and EMG Active Accessory onto the body or pickguard.
Plug both pickup cables into the B245 Pickup Buss (BLACK Shroud) as shown.
Refer to diagram #2, Bridge Pickup to Position 1 and Neck Pickup to Position 2
3) Strip the insulation from the switch wires and Insert them into the GREEN
Terminal Block and tighten the screws with a small screwdriver.
The Bridge pickup goes to the BR Terminal
The Neck pickup goes to the NK Terminal
The Output of the switch goes to the O Terminal
If there is a ground wire coming from the switch, insert it into one of the black
GND terminals on the block.
If using a solderless EMG 3-way toggle, refer to Diagram #5.
4) Plug a connect cable from the Pickup Buss (Position 3) to the Input of the Active
Accesory control as shown in the diagram below.
5) Plug a connect cable from the Output of the Active Accessory to the Master Volume
as shown.
6) Plug the output cable onto the Master Volume control and connect the output
wires to the output jack by pushing the connectors on as shown.
WHITE wire onto the TIP (T) contact,
BLACK wire onto the SLEEVE (S) contact
BLACK Battery Negative wire onto the RING (R) contact.
7) Plug the RED wires of the pickups onto the V+ Buss (RED Shroud)
along with the RED wire of the battery clip and the EMG Active Accessory.
8) Wrap the battery in a piece of insulating foam and place it securely in the
control cavity.
9) Before restringing your instrument, perform a “tap test” as previously
described to check that your setup performs as expected.
2 Pickups / Toggle Select Switch / Master Volume / Active Accessory (SPC, EXG, VLPF, etc.)
Note: This configuration utilizes an active accessory that is not included in the JMASTER Set.
Additional solderless controls are available at emgpickups.com
- 9V +
NOTE REVERSED CONNECTOR
ACTIVE ACCESSORY
(SPC, VLPF, etc.)
Note the orientation of the connect cable at the Input; This “reversed”
connection method is common to nearly all EMG Active Accessories like
the SPC, EXG, RPC, Afterburner, and more.