Ground Zero PLUTONIUM SERIES Troubleshooting guide

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PLUTONIUM SERIES
Amplifier
GZPA 2SQ
GZPA 4SQ
Owner’s Manual
& Installation Guide
English

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Introduction
Thank you for choosing a GROUND ZERO product and welcome to your new PLUTONIUM series amplifier!
This is the owner´s manual providing instructions on the operation and installation of this high-end car
amplifier. Please, read it carefully. If you have any further questions, please contact your local
Ground Zero dealer or our regional distribution partner.
The amplifier is one of the most important parts of your car audio system. However, it will only be able to
deliver its full performance when each part of the whole system is tuned carefully matching each other.
Therefore, we recommend consulting a car audio specialist to compile the desired sound system,
as well as for installation and tuning.
We hope you will enjoy the sound quality of an enthusiastic development
by the Ground Zero engineering team!
PLUTONIUM Series – The High-End Experience
Products belonging to the GROUND ZERO PLUTONIUM series stand for high-end sound quality
or extreme power handling capability.
To achieve one of these targets, exceptional materials and technologies are applied during the development.
The technical, electrical and mechanical skills of the resulting products convince not only during worldwide
sound quality competitions but also satisfy the demands of high-end enthusiasts with outstanding audio
reproduction ability.
Starting from the market release, the subwoofers have set benchmarks in SPL competitions around the world
and have been awarded for best performance by numerous test magazines.
The GZPA SQ amplifiers have been developed by experienced sound quality engineers and tuned by music
loving enthusiasts. They are being built with highest care using some of the best quality parts available
and run through numerous tests prior to handing over to GROUND ZERO partners and retail shops.
Terms of Warranty
The limited warranty for this product is covered by GROUND ZERO´s regional distribution partners and their
terms and conditions. For further information contact your local retailer or regional distributor.

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PLUTONIUM SERIES
Amplifiers
GZPA 2 SQ
GZPA 4 SQ
Features
•High-End SQ amplifier
•Shielded dual power supply
•Discretely constructed MOS-FET amplifier section
•1-ohm stable stereo / 2-ohms stable in bridged mode
•Smoothly variable BIAS adjustment
•Variable input sensitivity
•Capsulated potentiometers
•Wide range high pass and low pass filter
•Filter range multiplication switch (x10)
•Wide frequency range for high resolution music (10 Hz – 50 kHz)
•Soft start delay
•Operation and protection indicator
•Start-Stop capability (9 -16 Volt)
•Overheat and short circuit protection
•Low distortion Burr-Brown OPA2134PA operation amplifier
•Ground Zero exclusive Mundorf Mcap® capacitors
•Solid and high efficient black anodized heatsink
•White illuminated lasered glass logo plate
•Phase control (GZPA 2SQ)
•Pure Direct mode (GZPA 2SQ)

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General installation note
•As a precaution, it is recommended to disconnect the vehicles battery before mounting the amplifier.
(Note: For new vehicles, disconnecting the battery might cause various errors in your vehicle´s
electric system that can be cleared only by authorized service partners of your vehicle´s
manufacturer! Please ask your service partner first before disconnecting the battery!)
•The power supply wire (+12 V) has to be protected within max. 20 cm / 8” by a main fuse holder
with a fuse value matching the recommendation for your amplifier
(Note: If there is more than one amplifier connected using this power wire, the main fuse value must
be equal to the sum of the recommended fuses of all connected devices. However, make sure the
diameter of your power wire will be sufficient for the required current!)
•If necessary, replace a defective fuse by a fuse with identical quality and value
•Never drill a hole to the vehicles gas tank or brake lines, to wirings or any other important vehicle
parts!
•Never pass wires over sharp edges or vehicle parts due avoid any kind of damage
•Keep the wiring away from the antenna and electronic devices contributing to radio reception
•Lay the power supply wiring always separated from speaker wiring to avoid disturbance
•The amplifier contains a temperature protection circuit that turns the device off in case of
overheating. After a certain cooling time, it will turn on automatically. To avoid heat build-up,
sufficient air supply for cooling must be provided. Never cover the surface of the amplifier´s
heatsink entirely
•The amplifier should NEVER be mounted onto a vibrating part or surface such as a subwoofer
enclosure. This might lead to malfunction due to loose electrical parts inside the amplifier.
•Some amplifiers offer a high-level input option, however if a pre-amplified output (RCA) is available
(at the head unit), it is strongly recommended to make use of them.

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Controls and functions GZPA 2SQ
BIAS adjustment
Adjusting the BIAS setting influences the operation mode and sound of the amplifier. Increasing the BIAS
setting clockwise leads to a warm sound experience with wide stereoscopic sound comparable to the
performance of a Class A amplifier with increased current consumption und heat generation. Reducing the
BIAS setting counterclockwise results in direct and clear music reproduction. Depending on the speaker´s
characteristics and the mounting positions, the adjustment is up to the listener´s taste of music reproduction.
The BIAS setting however, does not influence the general output power of the amplifier
LED illumination
Optionally, the LED illumination of the Ground Zero logo can be switched off. For this purpose, the jumper
positioned on the back side of the top aluminum cover needs to be removed from the illumination pc board.
1
Power terminal
GROUND Vehicle ground connection
REMOTE Remote connection (turn-on voltage)
BATT+ 12 Volt (Battery)
2
Speaker terminal
Speaker wire connection
3
Signal input
RCA wire connection
4
Input sensitivity
Control for correct input sensitivity adjustment
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High pass switch
Switch to activate the high pass filter
6
High pass multiplier
Switch to multiply (x10) the high pass filter frequency range
7
High pass frequency
Control to adjust the correct high pass filter frequency
8
Low pass switch
Switch to activate the low pass filter
9
Low pass multiplier
Switch to multiply (x10) the low pass filter frequency range
10
Low pass frequency
Control to adjust the correct low pass filter frequency
11
Bypass function
Switch to deactivate both crossover filters (Direct signal path)
12
Phase switch
Switch to activate the phase adjustment control
13
Phase adjustment
Control to adjust the correct phase
14
BIAS adjustment
Control to adjust the BIAS setting (check the BIAS adjustment info below)
15
Status indication
POWER (white) indicates the correct operation mode
PROTECT (red) indicates a defect / activated protection mode

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Connections GZPA 2SQ – stereo mode
Connections GZPA 2SQ – bridged mode

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Controls and functions GZPA 4SQ
BIAS adjustment
Adjusting the BIAS setting influences the operation mode and sound of the amplifier. Increasing the BIAS
setting clockwise leads to a warm sound experience with wide stereoscopic sound comparable to the
performance of a Class A amplifier with increased current consumption und heat generation. Reducing the
BIAS setting counterclockwise results in direct and clear music reproduction. Depending on the speaker´s
characteristics and the mounting positions, the adjustment is up to the listener´s taste of music reproduction.
The BIAS setting however, does not influence the general output power of the amplifier
LED illumination
Optionally, the LED illumination of the Ground Zero logo can be switched off. For this purpose, the jumper
positioned on the back side of the top aluminum cover needs to be removed from the illumination pc board.
1
Power terminal
GROUND Vehicle ground connection
REMOTE Remote connection (turn-on voltage)
BATT+ 12 Volt (Battery)
2
Speaker terminals
Speaker wire connections
3
Signal input
RCA wire connection
4
Input sensitivity
Control for correct input sensitivity adjustment
5
High pass switches
Switches to activate the high pass filter (separately for front and rear)
6
High pass multipliers
Switches to multiply (x10) the high pass filter frequency range
7
High pass frequency
Controls to adjust the correct high pass filter frequency
8
Low pass switch
Switches to activate the low pass filter (separately for front and rear)
9
Low pass multiplier
Switches to multiply (x10) the low pass filter frequency range
10
Low pass frequency
Controls to adjust the correct low pass filter frequency
14
BIAS adjustment
Controls to adjust the BIAS setting (check the BIAS adjustment info
below) for each pair of channels separately
15
Status indication
POWER (white) indicates the correct operation mode
PROTECT (red) indicates a defect / activated protection mode

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Connections GZPA 4SQ – stereo mode
Connections GZPA 4SQ – bridged mode

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Trouble shooting
The amplifier includes protection features to prevent any kind of damage caused by misuse or faulty
conditions. Sensor-detected short circuit at the speaker terminals or an impedance below the permitted value
lights up the protection indicators and turns off the amplifier.
To determine the problem, the volume should be reduced to minimum, the power supply disconnected, and
the installation checked carefully for wiring mistakes or defects.
If the amplifier shuts down due to excessive heat, the protection indicators will not light up. In this case the
amplifier just needs a certain time to cool down.
Check the following table to solve a problem. It´s recommended to check the speakers and speaker wires
first, whenever the protection mode has been activated (PROTECT).
Problem
Check point
Reason / action
No audible signal
POWER indication status
Check the fuse(s)
Check the power connection
Check the ground connection
Check the remote wire connection
PROTECT indication status
Speaker short circuit
Check the speakers and speaker wires
Amplifier overheated
Wait for cooling down
Probably damaged amplifier
Contact a Ground Zero service partner
Amplifier is not switching
to operation mode
Power supply Check the fuse(s)
Check the power connection
Check the ground connection
Remote (turn-on) voltage
Check the remote (out) voltage at the head unit
Amplifier switches off or
into protection mode at
high levels
Speaker impedance
Speaker wiring
Check if the impedance at the speaker wire
dropped below the permitted value
No audible signal at one
of the amplifiers channels
RCA cable / speaker wires
Check the terminals and RCA connectors
(check the audio signal on each RCA cable)