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GR8A

 

U

SER 

G

UIDE

 

 

INSTALLATION 

The 

GR8A

 can be rack or desk top mounted.  It is supplied with rack ears 

and desk feet fitted.  These may be removed according to the installation 
required. 

 

RACK MOUNT

   The 

GR8A

 fits into a 2U space in a standard 19” rack 

system.  The rack should allow a minimum side to side opening of 445mm 
and a depth of at least 420mm to include the connector space required.  
Secure the unit into the rack using two M6 bolts on each side.  These are 
usually provided by the rack supplier and are typically chrome or black 
bolts that seat in black plastic cups to prevent scratching the equipment 
panel.  If space is tight beneath the unit you can remove the plastic feet by 
prizing them off.  It is advisable to mount the heavier units such as 
amplifiers towards the bottom of the rack.  This lowers the centre of gravity 
for easier handling. 

 

DESK OR SHELF MOUNT

   Remove the two rack ears.  Use a crosspoint 

screwdriver to remove the two M4 fixing screws on each side.  Make sure 
the plastic feet are fitted as these protect the mounting surface from 
scratching and prevent the unit sliding. 

 

CABLE ROUTING

   It is well known that the majority of hum, noise and 

routing problems are caused by poor connections and cables.  Use high 
quality cable and connectors and check for reliable soldering and 
assembly.  Use balanced connections and screened cables for the inputs.  
If you have problems with ground loops lift the screen connection at one 
end of the input cables or operate the source equipment ground lift 
switches.  Use adequately rated speaker wire for the outputs.  Input cables 
may be run together but outputs should be separated to avoid interaction 
between the amplifiers.  Route all input and output cables away from 
mains, computer and lighting cables. 

 

IMPORTANT WARNINGS ! 

When positioning the GR8A ensure that the front air intake and the 
exhaust vent on the left hand side of the unit are not obstructed or 
blocked. 

It is normal for the amplifier to run hot when it is working hard.  It is 
important that air flow around the unit is not restricted.  If free air 
flow is restricted then additional forced cooling should be provided. 

The GR8A is a heavy item.  Ensure it is securely fixed where it will 
not fall or slip and cause damage or injury. 

To avoid damage to the internal assemblies do not fit screws or drill 
holes in the sides or underside of the unit.  Secure to external 
brackets or fittings through the front panel rack mounting holes. 

Ensure that the mains voltage setting marked on the rear panel is the 
same as your local mains supply. 

Do not remove the top cover.  There are no user serviceable parts 
inside.  Refer servicing to qualified service personnel. 

To ensure your safety make sure that all the chassis and metalwork 
in the rack system is connected to mains earth.  Use a continuity 
meter to check this.  Do not remove any safety earths from 
equipment. 

Содержание GR8A

Страница 1: ...8 Channel Amplifier GR8A USER GUIDE Publication AP4298 ...

Страница 2: ... of performance and reliability for which this equipment has been designed and manufactured read this User Guide before operating In the event of a failure notify and return the defective unit to ALLEN HEATH or its authorised agent as soon as possible for repair under warranty subject to the following conditions Conditions Of Warranty The equipment has been installed and operated in accordance wit...

Страница 3: ... remove this connection CONTENTS Warranty 2 Safety Warnings 3 Welcome to the Allen Heath GR8A 4 General Precautions 4 Specifications 5 Front Panel Controls 6 Rear Panel Controls and Connectors 7 Installation 9 Operation 10 Block Diagram 11 SAFETY WARNING Mains electricity is dangerous and can kill Mains voltage is present within the GR8A Do not remove the top cover There are no user serviceable pa...

Страница 4: ... Remote output standby control per channel Service And Technical Support Under normal operating conditions the GR8A does not require user maintenance or calibration apart from occasional vacuuming of the air intake filter should it become ingrained with dust To avoid damage to internal components by mishandling and or misconnection service work should be referred only to technically competent pers...

Страница 5: ... into 8 ohms Peak transient power Unbridged 130W into 4 ohms Bridged 250W into 8 ohms Slew rate 10V uS Frequency response 20Hz to 20kHz 0 0 5dB Total Harmonic Distortion 6W into 8 ohms 1kHz 0 03 Signal to noise ratio Relative to 60W into 4 ohms 100dB Stand by Separate control per channel Control Switch common 15V to channel pin Attenuation 80dB Inter channel Crosstalk relative to 60W into 4 ohms 1...

Страница 6: ...ontrol that adjusts its level from fully off to maximum sensitivity In bridged mode the odd numbered channel control sets the overall level and the even numbered control is not used Use the level controls to match the amplifiers to the connected source equipment set maximum volume allowed or adjust the balance between different outputs Blanking plugs are provided for situations where tamper proof ...

Страница 7: ...d and wired pin 2 hot Input sensitivity is 4dBu for rated power output Good quality 2 core screened signal cable should be used for these inputs to avoid signal degradation or interference pickup over long cable runs Use balanced connections where possible INPUT MODE switches Three tamperproof underpanel switches configure the inputs to allow different combinations of common input sourcing Use the...

Страница 8: ...o select bridge mode using a pen or similar pointed object This configures two amplifiers to work together into one speaker Use bridge mode when you need a lot more amplifier power to drive a single speaker BRIDGE MODE Use the odd numbered channel input and controls The even numbered input is disabled You should blank off the unused level controls using the plugs provided The front panel BRIDGE in...

Страница 9: ...nd screened cables for the inputs If you have problems with ground loops lift the screen connection at one end of the input cables or operate the source equipment ground lift switches Use adequately rated speaker wire for the outputs Input cables may be run together but outputs should be separated to avoid interaction between the amplifiers Route all input and output cables away from mains compute...

Страница 10: ...amplifier level controls to correct the signal matching These controls can also be used to preset the maximum volume allowed for each output or to balance the volume between different outputs Remove the knobs and fit the blanking plugs provided with the unit if you wish to lock the controls and make them tamperproof Metering A 3 colour signal meter indicator is provided for each channel to monitor...

Страница 11: ...GR8A USER GUIDE 11 BLOCK DIAGRAM ...

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