JBL GTQ 190 (serv.man2) User Manual / Operation Manual ▷ View online
13
Owner’
s Manual
In Case of Difficulty
Power-on light does not come on
• Head unit not on; turn the head unit on.
• Ground wire is disconnected or defective;
check for continuity with an ohmmeter
between the amplifier’s ground terminal and
a known chassis ground point.
• Battery wire is disconnected or defective;
check for approximately
• Head unit not on; turn the head unit on.
• Ground wire is disconnected or defective;
check for continuity with an ohmmeter
between the amplifier’s ground terminal and
a known chassis ground point.
• Battery wire is disconnected or defective;
check for approximately
+
12 volts between
the amplifier’s battery and ground terminals.
• Blown fuse; check amplifier’s fuses located
on the end panel near the power connector.
If they are blown, replace them with
identical ones. If the new fuses blow
immediately, check all the wiring
connections. If the source of the problem
cannot be determined, consult your JBL
dealer.
• Remote-on wire between the head unit and
the amplifier is disconnected or defective;
check for
• Blown fuse; check amplifier’s fuses located
on the end panel near the power connector.
If they are blown, replace them with
identical ones. If the new fuses blow
immediately, check all the wiring
connections. If the source of the problem
cannot be determined, consult your JBL
dealer.
• Remote-on wire between the head unit and
the amplifier is disconnected or defective;
check for
+
12 volts between amplifier's
remote-on input terminal and the ground
wire with the head unit on.
wire with the head unit on.
Power light is on, but no sound is heard
from some or all of the speakers
from some or all of the speakers
• Incorrect switch settings; make sure that all
switches (mode, input and crossover) are in
their correct positions for your system
configuration.
• Incorrectly connected or shorted speaker
wires; check for shorts in wiring.
• Defective or disconnected audio cables;
check for continuity and replace if necessary.
• Incorrect gain adjustment; verify that the
amplifier gain controls are not turned
completely down. If they are, sound output
level may be very low and may give the
impression that the system (or part of the
system) is dead.
switches (mode, input and crossover) are in
their correct positions for your system
configuration.
• Incorrectly connected or shorted speaker
wires; check for shorts in wiring.
• Defective or disconnected audio cables;
check for continuity and replace if necessary.
• Incorrect gain adjustment; verify that the
amplifier gain controls are not turned
completely down. If they are, sound output
level may be very low and may give the
impression that the system (or part of the
system) is dead.
Power light is on, but no sound is heard
from some or all of the speakers
from some or all of the speakers
• Defective head unit or signal processor;
check each component for proper wiring and
operation.
• Defective GTQ amplifier; if there is audio
signal present at the inputs of the amplifier
and there is no output, the GTQ amplifier
may be defective.
check each component for proper wiring and
operation.
• Defective GTQ amplifier; if there is audio
signal present at the inputs of the amplifier
and there is no output, the GTQ amplifier
may be defective.
Alternator whine through the audio system
with the engine running
with the engine running
• Ground loops; follow the wiring sugges-
tions in the section called “Solving Noise
Problems.” Also, verify that the chassis
grounding point you have chosen is true
ground by checking for continuity between
the chassis ground point and battery ground.
tions in the section called “Solving Noise
Problems.” Also, verify that the chassis
grounding point you have chosen is true
ground by checking for continuity between
the chassis ground point and battery ground.
Bass output from speakers too low
• Speaker wired out of phase; check for
proper polarity on all speaker wiring (
proper polarity on all speaker wiring (
+
amp
terminal to
+
speaker terminal and – amp
terminal to – speaker terminal).
Power light is blinking and no sound is
heard
heard
• Incorrectly connected or shorted speaker
wires; check for shorts in wiring.
• Defective GTQ amplifier; if there is no short
on the speaker outputs, the GTQ amplifier
may be broken. Consult your JBL dealer.
wires; check for shorts in wiring.
• Defective GTQ amplifier; if there is no short
on the speaker outputs, the GTQ amplifier
may be broken. Consult your JBL dealer.
If you want to talk to us about any problems,
call JBL Customer Service at 1-800-336-4JBL
between 9AM and 5PM Eastern time.
call JBL Customer Service at 1-800-336-4JBL
between 9AM and 5PM Eastern time.
Solving Noise Problems
System Noise
System noise, generally appearing as
hiss, is usually the result of improper
input gain (sensitivity) adjustment. With
the proper setting, your JBL amplifier will
not create this noise, but will amplify any
noise generated ahead of it as part of the
signal. Refer to “Adjusting the Gain”
section on page 11 for instructions on
how to minimize this noise.
hiss, is usually the result of improper
input gain (sensitivity) adjustment. With
the proper setting, your JBL amplifier will
not create this noise, but will amplify any
noise generated ahead of it as part of the
signal. Refer to “Adjusting the Gain”
section on page 11 for instructions on
how to minimize this noise.
Vehicle Noise
Every vehicle has some electrical noise
that is generated by the ignition system,
the alternator, the accessories, and their
wiring. High-performance audio
equipment is more likely to pick up such
noise than conventional equipment
because it has wide-frequency bandwidth
and high-gain (amplification) circuits.
GTQ amplifiers have two built-in power
supply filters to help prevent noise
problems. If noise occurs it is probably
the result of improper installation. The
following suggestions will help you
eliminate most noise problems.
Source Noise –
that is generated by the ignition system,
the alternator, the accessories, and their
wiring. High-performance audio
equipment is more likely to pick up such
noise than conventional equipment
because it has wide-frequency bandwidth
and high-gain (amplification) circuits.
GTQ amplifiers have two built-in power
supply filters to help prevent noise
problems. If noise occurs it is probably
the result of improper installation. The
following suggestions will help you
eliminate most noise problems.
Source Noise –
Often noise in a system
is picked up by the signal source. Before
attempting to eliminate noise from the
amp, be sure it is not being picked up by
the signal source and then passed on to
other components. To do this, connect
the signal source output to an external
amplifier which has no other connection
to the vehicle except for the audio signal
leads. A battery-powered amplified
portable speaker, such as those sold for
use with com-puters or Walkman-type
attempting to eliminate noise from the
amp, be sure it is not being picked up by
the signal source and then passed on to
other components. To do this, connect
the signal source output to an external
amplifier which has no other connection
to the vehicle except for the audio signal
leads. A battery-powered amplified
portable speaker, such as those sold for
use with com-puters or Walkman-type
portables, works well for this. Listen to
see if the noise is present in the signal
from the source unit. If so, consult the
manufacturer of the source unit, or your
JBL dealer, for help in reducing this
noise. If there is no noise in this signal, it
can be eliminated as the source of your
problems.
Ground Loops –
see if the noise is present in the signal
from the source unit. If so, consult the
manufacturer of the source unit, or your
JBL dealer, for help in reducing this
noise. If there is no noise in this signal, it
can be eliminated as the source of your
problems.
Ground Loops –
The vast major-ity of
noise problems are caused by
inadequate or improper grounding. The
head unit, the amplifier, and any other
components must be grounded to a
major metal member of the vehicle’s
frame. Make sure to choose a solid metal
ground point, as some new vehicles
contain structural elements made of
plastic.
Most often the noise level in the system
will be lower if amplifiers and signal
processors that do not have isolated
supplies are all grounded to the same
point on the chassis. Amplifiers, such as
the GTQs, which internally isolate the
signal ground connection from the power
ground connection, generally do not
benefit from this. Usually the head unit
does not need to be grounded to the
same point as the rest of the system, but
in some instances, depending on the
design of the signal processors involved,
grounding signal processors to the same
point as the head unit will also help. If
this does not adequately reduce the
noise level, try another ground point on
the car frame. Because of current flow
patterns within the vehicle chassis, some
ground points are noisier than others. As
a general rule, try to keep grounds away
from the main flow of current between
inadequate or improper grounding. The
head unit, the amplifier, and any other
components must be grounded to a
major metal member of the vehicle’s
frame. Make sure to choose a solid metal
ground point, as some new vehicles
contain structural elements made of
plastic.
Most often the noise level in the system
will be lower if amplifiers and signal
processors that do not have isolated
supplies are all grounded to the same
point on the chassis. Amplifiers, such as
the GTQs, which internally isolate the
signal ground connection from the power
ground connection, generally do not
benefit from this. Usually the head unit
does not need to be grounded to the
same point as the rest of the system, but
in some instances, depending on the
design of the signal processors involved,
grounding signal processors to the same
point as the head unit will also help. If
this does not adequately reduce the
noise level, try another ground point on
the car frame. Because of current flow
patterns within the vehicle chassis, some
ground points are noisier than others. As
a general rule, try to keep grounds away
from the main flow of current between
GTQ 190 - English 06/03/98 11:50 Side 13
14
the battery and alternator. For example,
in a vehicle with a battery at the right
rear and an alternator at the left front,
you are most likely to find a quiet ground
at the far left rear than anywhere
between the battery and alternator. In
some rare instances with plastic-bodied
vehicles, grounding the equipment
directly to the battery will provide the
best results, although usually this
provides poor results with most cars and
is not recommended.
In complex systems involving
components from different
manufacturers, it helps to know the type
of power supplies used in each
component. For low-level signal
processors such as equal-izers or
electronic crossovers, a manufacturer
may use either a power supply which is
isolated through a DC-to-DC converter, or
a simple regulated supply from the
in a vehicle with a battery at the right
rear and an alternator at the left front,
you are most likely to find a quiet ground
at the far left rear than anywhere
between the battery and alternator. In
some rare instances with plastic-bodied
vehicles, grounding the equipment
directly to the battery will provide the
best results, although usually this
provides poor results with most cars and
is not recommended.
In complex systems involving
components from different
manufacturers, it helps to know the type
of power supplies used in each
component. For low-level signal
processors such as equal-izers or
electronic crossovers, a manufacturer
may use either a power supply which is
isolated through a DC-to-DC converter, or
a simple regulated supply from the
+
12V
vehicle battery. The important
characteristic to know is how well the
power ground is isolated from the signal
ground (phono-plug shield) in each
component. Many simple signal
processors or low-powered amplifiers
have no isolation. These can be identified
by a direct connection from power
ground to the shield of the RCA jacks
(measured with an ohmmeter with no
other connections present). For these
components, the best ground connection
may be one where the power ground
wire is not connected at all! The RCA
cables will provide the ground
connection to the source unit. Please note
that this is only appropriate for units
which draw less than 500mA of current.
characteristic to know is how well the
power ground is isolated from the signal
ground (phono-plug shield) in each
component. Many simple signal
processors or low-powered amplifiers
have no isolation. These can be identified
by a direct connection from power
ground to the shield of the RCA jacks
(measured with an ohmmeter with no
other connections present). For these
components, the best ground connection
may be one where the power ground
wire is not connected at all! The RCA
cables will provide the ground
connection to the source unit. Please note
that this is only appropriate for units
which draw less than 500mA of current.
Higher power units of this type, such as
amplifiers, are best connected with their
ground wires connected directly to the
chassis of the head unit.
The trickiest grounding task is created
when some components of this type are
mixed with other components using
isolated supplies. For this type of system,
the following grounding scheme will
usually work:
1. Connect the head unit chassis to a solid
vehicle ground using a short, heavy
gauge wire (AWG10). Do not connect this
to the vehicle’s wiring harness, but go
directly to a metal part of the vehicle.
2. Connect all signal-processor grounds
directly to the head unit chassis at the
same point. Run each wire individually.
Due to wire resistance, connecting
multiple wires to a single wire, then
running the single wire to the head unit,
is not the same!
3. Connect all amplifier grounds directly
to the vehicle chassis but not necessarily
to the same point as the head unit.
Power-line Noise –
amplifiers, are best connected with their
ground wires connected directly to the
chassis of the head unit.
The trickiest grounding task is created
when some components of this type are
mixed with other components using
isolated supplies. For this type of system,
the following grounding scheme will
usually work:
1. Connect the head unit chassis to a solid
vehicle ground using a short, heavy
gauge wire (AWG10). Do not connect this
to the vehicle’s wiring harness, but go
directly to a metal part of the vehicle.
2. Connect all signal-processor grounds
directly to the head unit chassis at the
same point. Run each wire individually.
Due to wire resistance, connecting
multiple wires to a single wire, then
running the single wire to the head unit,
is not the same!
3. Connect all amplifier grounds directly
to the vehicle chassis but not necessarily
to the same point as the head unit.
Power-line Noise –
The built-in power
supply filter of the ampli-fier makes
external filters unnecessary. In some
cases, power supply noise can enter the
system through the head unit power
supply or the supply of an equalizer or
other signal processor. Putting a filter on
the head unit or signal processor power
supply input may then be helpful. Using a
portable powered speaker as described in
the “Source Noise” section can help you
isolate an individual component which
may be sensitive to this. Start at the head
unit, and work back, checking each
component individually.
external filters unnecessary. In some
cases, power supply noise can enter the
system through the head unit power
supply or the supply of an equalizer or
other signal processor. Putting a filter on
the head unit or signal processor power
supply input may then be helpful. Using a
portable powered speaker as described in
the “Source Noise” section can help you
isolate an individual component which
may be sensitive to this. Start at the head
unit, and work back, checking each
component individually.
Power wires carrying high currents may
induce noise in nearby signal wires.
Make sure that power wires and signal
wires do not run together for long
distances. When power and signal leads
must cross, they should cross at right
angles. If you suspect that power line
noise is being induced in the signal
leads, you can repeat the test for source
noise described previously, but perform
the test at the amplifier end of the signal
cables. One power wire that will be
impossible to stay away from is the
vehicle chassis. The chassis is one giant
ground wire! Use high-quality shielded
cables, twisted pair, or a balanced-line
system for the long front-to-rear signal
runs to reduce the likelihood of noise
pickup from this source.
Other Noise Sources –
induce noise in nearby signal wires.
Make sure that power wires and signal
wires do not run together for long
distances. When power and signal leads
must cross, they should cross at right
angles. If you suspect that power line
noise is being induced in the signal
leads, you can repeat the test for source
noise described previously, but perform
the test at the amplifier end of the signal
cables. One power wire that will be
impossible to stay away from is the
vehicle chassis. The chassis is one giant
ground wire! Use high-quality shielded
cables, twisted pair, or a balanced-line
system for the long front-to-rear signal
runs to reduce the likelihood of noise
pickup from this source.
Other Noise Sources –
Common noise
problems will be solved by proper
grounding and power supply
connections. However, there are impulse-
type noise sources which may require
suppression at the noise source. Many
noise suppression devices (such as spark
plug and coil lead suppressors, and rotor
and coil bypass capacitors) are available
at auto parts or car stereo stores. There
are also noise suppressors that can be
connected directly to the alternator that
are effective in some situations. The use
of any such suppressor should be
discussed with a JBL authorized
installation specialist after the basic
grounding scheme and power
connections are confirmed to be correct.
Certain vehicles are particularly noisy,
especially models that have solid-state
ignition systems or that have non-metal
grounding and power supply
connections. However, there are impulse-
type noise sources which may require
suppression at the noise source. Many
noise suppression devices (such as spark
plug and coil lead suppressors, and rotor
and coil bypass capacitors) are available
at auto parts or car stereo stores. There
are also noise suppressors that can be
connected directly to the alternator that
are effective in some situations. The use
of any such suppressor should be
discussed with a JBL authorized
installation specialist after the basic
grounding scheme and power
connections are confirmed to be correct.
Certain vehicles are particularly noisy,
especially models that have solid-state
ignition systems or that have non-metal
bodies. Such vehicles may require
electrical noise suppression devices
which are not normally needed.
Antenna –
electrical noise suppression devices
which are not normally needed.
Antenna –
A common noise problem is
generated by a ground loop produced by
the antenna shielded cable being
grounded at both the antenna mounting
point and at the head unit input. In this
instance, insulate the antenna ground
from the chassis of the vehicle at the
antenna mounting point so the antenna
shield is grounded only at the radio’s
antenna input. Commercial antenna
ground-loop isolators are also available.
Switching Noise –
the antenna shielded cable being
grounded at both the antenna mounting
point and at the head unit input. In this
instance, insulate the antenna ground
from the chassis of the vehicle at the
antenna mounting point so the antenna
shield is grounded only at the radio’s
antenna input. Commercial antenna
ground-loop isolators are also available.
Switching Noise –
GTQ amplifiers have
highly developed switching power
supplies which generate some RF
interference as a result of their switch-
mode operation. Although this is
internally filtered and shielded by the
GTQ ampli-fier chassis, some unusually
sensitive installations may pick up
switching noise, especially when listening
to weak AM radio stations. If this unusual
situation occurs, one of the following
installation corrections will typically
eliminate the problem.
1. Relocate the amplifier to a position
farther away from the radio or radio
antenna.
2. Move the electrical ground of the head
unit and/or amp to a different point on
the vehicle’s chassis.
3. Keep the amplifier power supply wiring
away from the radio or antenna wiring.
4. Wrap the
supplies which generate some RF
interference as a result of their switch-
mode operation. Although this is
internally filtered and shielded by the
GTQ ampli-fier chassis, some unusually
sensitive installations may pick up
switching noise, especially when listening
to weak AM radio stations. If this unusual
situation occurs, one of the following
installation corrections will typically
eliminate the problem.
1. Relocate the amplifier to a position
farther away from the radio or radio
antenna.
2. Move the electrical ground of the head
unit and/or amp to a different point on
the vehicle’s chassis.
3. Keep the amplifier power supply wiring
away from the radio or antenna wiring.
4. Wrap the
+
12-volt power supply wires
for the radio/tape deck and/or the GTQ
amplifier with metallized shielding tape
or ground braid, and ground the tape to
the chassis of the vehicle.
amplifier with metallized shielding tape
or ground braid, and ground the tape to
the chassis of the vehicle.
GTQ 190 - English 06/03/98 11:50 Side 14
15
Owner’
s Manual
Maintenance
GTQ amplifiers do not require any
regular maintenance. Periodically
checking the main power supply and
grounding points and terminal
connections is advisable. Be sure the
connections are solid and corrosion-free.
Loose or corroded connections can cause
annoying intermittent noise or unusual
operational problems. Do not allow dust
to accumulate on the amplifier heat
sinks. It will reduce the amplifier’s ability
to dissipate heat. Occasional vacuum-
cleaning will prevent dust accumulation.
regular maintenance. Periodically
checking the main power supply and
grounding points and terminal
connections is advisable. Be sure the
connections are solid and corrosion-free.
Loose or corroded connections can cause
annoying intermittent noise or unusual
operational problems. Do not allow dust
to accumulate on the amplifier heat
sinks. It will reduce the amplifier’s ability
to dissipate heat. Occasional vacuum-
cleaning will prevent dust accumulation.
Specifications
GTQ190
Power Output
30 Watts x 4 (4 Ohms, 0.05% THD)
(20Hz – 20kHz,
45 Watts x 4 (2 Ohms, 0.08% THD)
14.4V Battery Voltage)
95 Watts x 2 (Bridged 4 Ohms, 0.08% THD)
Signal-to-Noise Ratio
100dBA
Frequency Response
10Hz – 50kHz (
+
0, –1dB)
20Hz – 20kHz (
+
0, – 0.1dB)
Damping Factor
>
200
Slew Factor
>
5
Line-Level Input Sensitivity
100mV – 4V RMS
(For Rated Power)
Line-Level Input Impedance
10k Ohms
Speaker-Level Input Impedance
15 Ohm
Speaker-Level Input Sensitivity
200mV – 8V RMS
Preamp Output Level
Preamp Input:
V out = V in
Speaker Input:
V out = 1/2 V in
Minimum Speaker Impedance
Single-Ended (Non-Bridged):
Single-Ended (Non-Bridged):
2 Ohms
Bridged:
4 Ohms
Built-in Electronic
18dB per Octave Low-Pass Filter,
Crossover Frequency and Slope
Fixed Frequency: 80Hz
18dB per Octave High-Pass Filter,
Fixed Frequency: 120Hz
Fixed Frequency: 120Hz
Preamp Outputs
Fixed Full-Range Frequency Response:
10Hz – 50kHz (+0, –1dB)
10Hz – 50kHz (+0, –1dB)
Power Requirement
11 to 16V DC Negative Ground
Fuse Size
30 Amp ATC Type Fuse
Size (HxWxL)
2 x 8 x 10-7/8" (51 x 196 x 274mm)
Weight
10.2 lbs (4.62 kg)
Speaker-Level Input
Molex Mini-Fit Jr
Mating Connector
#39-01-2080
Metal Pins: 39-00-0038
Metal Pins: 39-00-0038
Declaration of Conformity
Kongevejen 194B
DK-3460 Birkerød
DENMARK
DK-3460 Birkerød
DENMARK
declare in own responsibility, that the product described
in this owner’s manual is in compliance with technical
standard:
EN 55 020/6.1988
Steen Michaelsen
Birkerød. DENMARK. 8/96
GTQ 190 - English 06/03/98 11:50 Side 15
15
Owner’
s Manual
Maintenance
GTQ amplifiers do not require any
regular maintenance. Periodically
checking the main power supply and
grounding points and terminal
connections is advisable. Be sure the
connections are solid and corrosion-free.
Loose or corroded connections can cause
annoying intermittent noise or unusual
operational problems. Do not allow dust
to accumulate on the amplifier heat
sinks. It will reduce the amplifier’s ability
to dissipate heat. Occasional vacuum-
cleaning will prevent dust accumulation.
regular maintenance. Periodically
checking the main power supply and
grounding points and terminal
connections is advisable. Be sure the
connections are solid and corrosion-free.
Loose or corroded connections can cause
annoying intermittent noise or unusual
operational problems. Do not allow dust
to accumulate on the amplifier heat
sinks. It will reduce the amplifier’s ability
to dissipate heat. Occasional vacuum-
cleaning will prevent dust accumulation.
Specifications
GTQ190
Power Output
30 Watts x 4 (4 Ohms, 0.05% THD)
(20Hz – 20kHz,
45 Watts x 4 (2 Ohms, 0.08% THD)
14.4V Battery Voltage)
95 Watts x 2 (Bridged 4 Ohms, 0.08% THD)
Signal-to-Noise Ratio
100dBA
Frequency Response
10Hz – 50kHz (
+
0, –1dB)
20Hz – 20kHz (
+
0, – 0.1dB)
Damping Factor
>
200
Slew Factor
>
5
Line-Level Input Sensitivity
100mV – 4V RMS
(For Rated Power)
Line-Level Input Impedance
10k Ohms
Speaker-Level Input Impedance
15 Ohm
Speaker-Level Input Sensitivity
200mV – 8V RMS
Preamp Output Level
Preamp Input:
V out = V in
Speaker Input:
V out = 1/2 V in
Minimum Speaker Impedance
Single-Ended (Non-Bridged):
Single-Ended (Non-Bridged):
2 Ohms
Bridged:
4 Ohms
Built-in Electronic
18dB per Octave Low-Pass Filter,
Crossover Frequency and Slope
Fixed Frequency: 80Hz
18dB per Octave High-Pass Filter,
Fixed Frequency: 120Hz
Fixed Frequency: 120Hz
Preamp Outputs
Fixed Full-Range Frequency Response:
10Hz – 50kHz (+0, –1dB)
10Hz – 50kHz (+0, –1dB)
Power Requirement
11 to 16V DC Negative Ground
Fuse Size
30 Amp ATC Type Fuse
Size (HxWxL)
2 x 8 x 10-7/8" (51 x 196 x 274mm)
Weight
10.2 lbs (4.62 kg)
Speaker-Level Input
Molex Mini-Fit Jr
Mating Connector
#39-01-2080
Metal Pins: 39-00-0038
Metal Pins: 39-00-0038
Declaration of Conformity
Kongevejen 194B
DK-3460 Birkerød
DENMARK
DK-3460 Birkerød
DENMARK
declare in own responsibility, that the product described
in this owner’s manual is in compliance with technical
standard:
EN 55 020/6.1988
Steen Michaelsen
Birkerød. DENMARK. 8/96
GTQ 190 - English 06/03/98 11:50 Side 15
