EMG BQS User guide

PO BOX 4394
SANTA ROSA, CA
95402 USA

0230-0216rK

P [phone]
F [phone]
EMGPICKUPS.COM

INSTALLATION INFORMATION
EMG MODEL: BQS SYSTEM

(ACTIVE PICKUP INPUT)

ABC (B118)
BALANCE
CONTROL

BASS
CONTROL

TREBLE
CONTROL

MID-RANGE
CONTROL

MASTER
VOLUME

ABOUT THE BQS SYSTEM:

The BQS System is a complete control system for bass guitars. Active Balance, Master Volume and EQ circuits are included. The EQ effects are
illustrated in the graphs on the next page. They allow you separate control over bass, midrange, and treble. Rotate the controls clockwise to
boost, counterclockwise to cut. There is a center detent for flat response.
The mid-range control has a variable frequency knob that allows you to sweep through the mid-frequency range from 100Hz to 1KHz. This
selects the frequency to boost or cut. The graphs on page 2 depict the frequency response of the controls.

Included in the system are:

1) Active Balance Control (B118)
The ABC Control is designed for EMG Active Pickups. It allows loss-free balance between two pickups and has a center detent for the middle
position. If you are using EMG-HZ Passive pickups, or other passive pickups you will want to use the B125 Active Balance Control which features
buffered inputs for passive high impedance pickups.

2) BQS Control 3-band equalizer for Bass guitar. The BQS features dual-pole filters for broadband equalization. The primary feature of the BQS
System is the variable mid-range frequency selection from 100 to 1KHz along with boost or cut of the chosen frequency. An additional feature
of the BQS Control is a 2-position dip-switch that controls the slope of the high frequency response. By choosing one of the four combinations
the high frequency response can be tailored to your liking.

3) Master Volume control, output jack, battery buss and clip.

Installation notes:
Battery Power:

If you play the instrument very hard, and are boosting the bass, mid, or treble with the BQS, you should consider operating the guitar on +18
Volts (2 Batteries in series, see page 4). If you play mildly and use a minimum of boost the instrument should operate easily on a single 9-Volt
battery. Use an Alkaline or Lithium battery for the best battery life and always unplug your guitar when you’re not using it.

wiring order:

Below is a diagram of the typical wiring order of the controls. Often the Volume control is closer to the pickups than the BQS Control making it
difficult to wire the instrument. It is preferable to have the Master Volume control last in the signal chain before the output jack. If this isn’t
possible it’s no worry, either wiring order is acceptable.

MASTER VOLUME AND
BQS CONTROL ORDER
CAN BE REVERSED

NECK
PICKUP

BRIDGE
PICKUP

ABC
CONTROL

MASTER
VOLUME

BQS

CONTROL

OUTPUT
JACK

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.

© 2014 Copyright EMG INC. All Rights Reserved.

Installation Instructions:
EMG Model: BQS System

High Frequency (Treble) Response Selection:

The BQS has the added feature of allowing you to choose from 4 different
high frequency response curves. This is a nice feature especially if you are
using the BQS with passive pickups. The following diagrams show the dip-switch
positions and the graphs show the resultant frequency response.
The BQC Control is an equalizer style control, offering both boost and cut
at the same frequency locations. The control also features a center detent
(click) that lets you know when no equalization is in effect.

ON/ON

BASS/TREBLE
CONTROL

TREBLE BOOST OR CUT (UPPER CONTROL)

BASS BOOST OR CUT (LOWER CONTROL)

OFF/ON

BQC CONTROL (TREBLE RESPONSE: ON/ON)

10 dB/div

20Hz

OFF/OFF

BQC CONTROL (TREBLE RESPONSE: 1 OFF/2 OFF)

10 dB/div

20Hz

Low Frequency (Bass) Response:

The BQC has a fairly standard bass response boost and cut. It’s slope is
6dB per octave and is centered at 50Hz. As you can see in the graph
on the left the signal can be boosted by +12db (Red Line) or cut by

-12dB (Green Line). A center detent (click) is provided on the control
to let you know when the frequency response is flat or unaffected
by boosting or cutting.

BQC CONTROL (TREBLE RESPONSE: 1 OFF/2 ON)

10 dB/div

10KHz1KHz

ON/OFF

BQC CONTROL (TREBLE RESPONSE: 1 ON/2 OFF)

10 dB/div

10KHz1KHz

20Hz

BQC CONTROL BASS RESPONSE

10 dB/div

10KHz1KHz20Hz

10KHz1KHz

BQS System Page 2

MID BOOST OR CUT (UPPER CONTROL)

MID FREQUENCY SELECTION (LOWER CONTROL)

20Hz

10KHz1KHz

Mid-Range Frequency Response:

One of the primary features of the BQC is it’s mid-range control. It allows you to
choose the frequency you want to boost or cut from 100 to 1000 Hz. The concentric
mid-range pot has two sections. The lower control chooses the frequency, while the
upper control lets you choose the amount of boost or cut you want. The maximum slope
is 12dB per octave at full gain or cut.. There is also a center detent (click) in the center
of the upper control to let you know when the control is not having any effect.

VARIABLE MID-RANGE FREQUENCY

1.0KHz100Hz

10 dB/div

20Hz

10KHz1KHz

Installation Instructions:
Plug-in Pickup Inputs:

If you already have EMG Active Pickups in your instrument you can use
the existing pickup cables or you can use the new pickup cables provided.
The new cables feature connectors on both ends to make the installation easier.

Diagram #1 illustrates how to connect the pickups to the ABC Control by using

the EMG plug-in connectors.

Diagram #1

Pickup Inputs

Cables from
Pickups

RED wires
from Pickups

Neck Pickup
(Upper 3-pin header)

Soldered inputs:

On the back side of the ABC PC Board there are 4 pads to solder to.
Solder the signal wire (Hot) of the bridge pickup to the BRG Pad,
and solder the ground wire (shield) of that pickup to the GND Pad.
Do the same for the Neck Pickup, Hot to the NEK Pad, and ground
to the GND Pad. Refer to Diagram #8 and solder the Red wires of
the pickups to the battery buss as shown.

Diagram #2
EMG Pickups
Soldered Inputs

Solder Pickup Hot to BRG Pad

Solder Pickup Ground to GND Pad

NK

V+

OUT

GND

BRG

BR

IN

V+

GND

Bridge Pickup Cable

Bridge Pickup
(Lower 3-pin header)

RED TO 9V + BUSS

Installation Instructions:
EMG Model: BQS System

Diagram #3 (preferred wiring order)
ABC Control
BQS Control
Master Volume
Output Jack

- 9V +

NECK
PICKUP

BRIDGE
PICKUP

OUTPUT TO
VOLUME CONTROL

ABC
CONTROL

RED

BQS

CONTROL

9V+ POWER BUSS

NEK

EMG,INC. B118rB

MASTER
VOLUME

GND

Neck Pickup Cable

Solder Pickup Ground to GND Pad

Solder Pickup Hot to NEK Pad

OUTPUT
JACK

EMG Neck Pickup
(Upper 3-pin header)

EMG Bridge Pickup
(Lower 3-pin header)

BQS System Page 3

RED WIRES
FROM PICKUPS

BASS

CONTROL

B118
ACTIVE BALANCE
CONTROL

RED

RED

NOTE:
REVERSED
CONNECTOR!

BQS

CONTROL

TREBLE

CONTROL

BATTERY

NEG (-) BLACK

MASTER
VOLUME

B122rH

VOLUME

OUTPUT CABLE

S

OUTPUT

R

T

BOTTOM
VIEW

Diagram #4 (alternate wiring order)
ABC
Master Volume
BQS Control
Output Jack

NECK
PICKUP

BRIDGE
PICKUP

ABC
CONTROL

RED

MASTER
VOLUME

CONTROL

9V+ POWER BUSS

BQS

OUTPUT
JACK

- 9V +

RED WIRES
FROM PICKUPS

EMG Active Neck Pickup

B118
ACTIVE BALANCE
CONTROL

(Upper 3-pin header)

EMG Active Bridge Pickup
(Lower 3-pin header)

RED

Diagram #5

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 (Red to Red and Black to Black) and
use the shrink tubing included to cover the connections.
Soldering the wires is recommended.

Cover these connections with the

shrink tubing provided.

RED to BATTERY OR PICKUP BUSS

9/18 VOLT
BATTERY
HOLDER

BLACK to RING terminal

of the Output Jack

BASS

CONTROL

BATTERY

NEG (-) BLACK

NOTE:
REVERSED
CONNECTOR

BQS

CONTROL

OUTPUT CABLE

MASTER
VOLUME

B122rH

VOLUME

RED

TREBLE

CONTROL

Diagram #6

+18 Volt Wiring Option:

If you want to operate your instrument at +18 Volts for more
headroom then use 2 batteries wired as below.
Also, if you are using any type of EQ in your instrument
(EMG-BT, BQ) or anything that boosts the pickup signal then
+18 Volts is recommended.

RED TO BATTERY BUSS (+18Volts)

- 9V +

- 9V +

BLACK

RED

BLACK to RING terminal

of the Output Jack

Solder the Black and Red
wires together and cover
the connection with shrink
tubing, or other insulation.

R

S

T

S

OUTPUT

R

T

BOTTOM
VIEW

Diagram #7

Soldering to the 152B Panel Jack:

If your instrument has a long Panel Jack like the one below
you will have to solder the output cable as shown.
Ground (Black) to the Sleeve
Signal (White) to the Tip
Battery Negative (Black) to the Ring

- 9V +

RED to BATTERY BUSS

BATTERY

NEG (-)

RING

FROM TONE

SLEEVE

OR VOLUME

BQS System Page 4

TIP

Diagram #8

Soldering to the battery buss:

If your instrument has an older EMG Pickup you can solder the
pickup RED wire to the buss. Simply use some needle nose pliers,
pull out the V+ header and solder the RED Wire from the pickup(s)
to any of the pins and then re-insert the header into the housing.

1

2

3