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PA-CP

 User Guide 

11 

Mains Power and Earthing 

Connecting Mains Power

   Read the SAFETY INSTRUCTIONS

 

printed at the front of this 

user guide and on the rear panel.  The power supply is wired for the local voltage required.  Check that 
the correct mains lead with moulded plug has been supplied with your console, and that the marked 
voltage matches your local supply.  Ensure that the IEC mains plug is pressed fully into the rear panel 
socket before switching on. 

 

To avoid any unexpected audible clicks or thumps 

turn connected power amplifiers down or off before 
switching the console or any other signal equipment on or 
off.

  The built-in amplifiers include an automatic turn on delay 

for this purpose.  

Switching On

   Press the rear panel ON/OFF switch in.  The 

front panel blue power LED lights.  You should hear the 
speaker relays switching in after a second or two.  This avoids 
audible thumps while the circuits stabilise.  The front panel SPK 
OFF indicators light while the speakers are isolated.  You may 
also hear air movement as the internal fans start up.  The 
meters and several other LED indicators may pulse briefly.  
This is quite normal. 

Switching Off   

Release the rear panel ON/OFF switch.  The 

relays switch off instantly to protect the speakers from any 
switch off thumps. 

 

Earthing

   The connection to earth (ground) in an audio system is important for two reasons: 

SAFETY to protect the operator from high voltage electric shock, and AUDIO PERFORMANCE to shield 
the audio from interference. 

For safety it is important that all equipment earths are connected to mains earth so that exposed metal 
parts are prevented from carrying high voltage which can injure or even kill the operator.  It is 
recommended that the system engineer check the continuity of the safety earth from all points in the 
system including microphone and instrument metal, equipment cases, rack frames, and so on. 

The same earth is also used to shield audio cables from external interference such as the hum fields 
associated with power transformers, lighting dimmer buzz, and computer  radiation.    Problems  arise 
when the signal sees more than one path to mains earth.  An ‘earth loop’ (ground loop) results causing 
current to flow between the different earth paths.  This condition is usually detected as a mains 
frequency audible hum or buzz. 

To ensure safe and trouble-free operation we recommend the following: 

 

Have your mains system checked by a qualified electrician

    If  the  supply  earthing  is  solid  to 

start with you are less likely to experience problems. 

 

Do not remove the earth connection from the console mains plug

  The console chassis is 

connected to mains earth through the power cable to ensure your safety.  Audio 0V is connected to 
the console chassis internally. 

 

Deal with ground loops

   Should you experience hum or buzz caused by earth loops, check first 

that each piece of equipment has its own separate path to earth.  If so, operate earth lift switches 
on connected equipment in accordance with the instruction manuals.  Alternatively, disconnect the 
cable screen at the destination end only.  This breaks the offending loop while still maintaining the 
signal shielding down the length of the cable. 

 

Use low impedance sources 

such as microphones and line level equipment rated at 200 ohms or 

less to reduce susceptibility to interference.  For high impedance instruments use DI (direct inject) 
boxes such as those readily available from most music equipment suppliers.  The console outputs 
are designed to operate at very low impedance to minimise interference problems. 

 

Use balanced connections for the microphone inputs and main outputs 

as these provide 

further immunity by cancelling out interference that may be picked up on long cable runs.  Refer to 
the cable diagrams for details on how to connect balanced and unbalanced equipment. 

 

Route cables to avoid interference

   To avoid interference pickup keep audio cables away from 

mains power units and cables, thyristor dimmer units or computer equipment.  Where this cannot 
be avoided, cross the cables at right angles to minimise interference. 

 

Use good quality cables and connectors 

and check for correct wiring and reliable solder joints.  

Use the correct cable type.  Allow sufficient cable loop to prevent damage through stretching.  

If you are not sure ... 

Contact your service agent or local Allen & Heath dealer for advice. 

CAUTION

RISK OF ELECTRIC SHOCK

8 OHMS

4 OHMS

CONSTANT POWER SWITCH

DO NOT OPEN

SERIAL NUMBER

FUSE

0

V AC  ~  47- 63 Hz

1600W MAX

MAINS INPUT

CAUTION:   FOR CONTINUED PROTECTION AGAINST RISK OF FIRE

ATTENTION:  REMPLACER LE FUSIBLE AVEC UN DES MEMES CARACTERISTIQ

SEE OPERATING MANUAL BEFORE USING.

NO USER SERVICEABLE PARTS INSIDE.

DO NOT OBSTRUCT VENTILATION OPENINGS.

RISK OF HAZARDOUS ENERGY! MAKE PROPER SPEAKER CONN

THIS APPARATUS MUST BE EARTHED BY THE POWER CORD.

DO NOT EXPOSE THIS APPARATUS TO RAIN OR MOISTURE.

AVIS: RISQUE DE CHOC ELECTRIQUE - NE PAS OUVRIR.

WARNING:  TO REDUCE THE RISK OF ELECTRIC SHOCK

100-240V  T10A L

ENGINEERED IN ENGLAND BY ALLEN & HEATH Ltd.

REPLACE F

ON/OFF

I

Содержание PA-CP Series

Страница 1: ...USER GUIDE Publication AP4956 PA CP Series Powered Mixer...

Страница 2: ...t development Allen Heath Limited Kernick Industrial Estate Penryn Cornwall TR10 9LU UK http www allen heath com Limited One Year Warranty This product is warranted to be free from defects in material...

Страница 3: ...le away from any equipment which produces heat such as power supplies power amplifiers and heaters Environment Protect from excessive dirt dust heat and vibration when operating and storing Avoid toba...

Страница 4: ...d service agents You can also access our Web site on the Internet for full company and product information To help us provide the most efficient service please keep a record of your console serial num...

Страница 5: ...nel pan 17 Using the channel faders 17 Using PFL 17 Using the stereo channels 18 Mixing two stereo signals into the channel 18 Sending ST1 3 direct to LR 18 Using the stereo channel equaliser 19 Effec...

Страница 6: ...useable speaker power so achieving the full 500W per side into 4 ohms or 8 ohms Full protection is provided including isolating relays short circuit and over current protection output sensing clip li...

Страница 7: ...e effects External stereo effects input to sum with internal effects AB amplifiers with slave output and amplifier breakpoint inputs 2 Track input for monitor and BGM replay 2 Track recording with ana...

Страница 8: ...ADER parametric output equaliser MAX 5k 5k O O 6 O O 6 O O O O 6 O O OO 6 6 6 15 15 15 6 O O O O 15 60Hz 15 60Hz 15 15 6 15 O O 6 MIN O O 6 10 O O 3 0 10 10 12kHz O O 12kHz O O 10 20 30 30 10 20 5 0 1...

Страница 9: ...rs Do not use bridged operation Set the rear panel CONSTANT POWER slide switch to the correct position for the speakers used 5 Plug in a music source Plug a CD player or similar test source into the S...

Страница 10: ...ater in this user guide The console can be rack mounted in either of two positions as described below 4 Rack Position 1 Shows the ears fitted for top of rack mounting The controls are angled upwards a...

Страница 11: ...qualified electrician If the supply earthing is solid to start with you are less likely to experience problems Do not remove the earth connection from the console mains plug The console chassis is con...

Страница 12: ...pment such as CD players and domestic amplifiers The Speakon connector type is used to feed the output of power amplifiers to the loudspeakers It can handle high power levels and can be locked into po...

Страница 13: ...diagrams Plugging into the line input automatically overrides the mic input Do not use Y adaptors to combine stereo L and R signals such as those from a CD player into one input Use the stereo or two...

Страница 14: ...t is 3dB down at its 100Hz cut off point and reduces the frequencies below that by 12dB every octave halving of frequency Using the filter The high pass filter is an invaluable tool for cleaning up th...

Страница 15: ...he equaliser It is best to keep the adjustments made using the equaliser as small as possible Use the microphones best suited for the application and ensure they are positioned carefully for optimum p...

Страница 16: ...used to add effects such as electronically simulated reverb or echo to the mix Turning up the FX control sends a portion of the channel signal to the internal effects unit where it is processed before...

Страница 17: ...monitors and house mix Press PFL You should hear the signal in your headphones and see its level displayed on the console meters Adjust the gain control so that the meters read an average 0 with loude...

Страница 18: ...channel Use a pen or similar pointed object to press the switch if you want to route the ST1 3 signal direct to the LR mix instead of the stereo channel Mixing two stereo signals into the channel Swit...

Страница 19: ...uieten a hissy keyboard some LF and HF cut to shape a reverb return and LF to cut back low frequency hum or resonance On the other hand a small amount of HF boost can brighten up a dull recording or a...

Страница 20: ...or stereo output is plugged into the EXT FX IN sockets GAIN matches it to the operating level of the channel The external signal sums with the internal effects and is routed through the FX fader to th...

Страница 21: ...ternal effects only MUTE Press this switch to turn the FX channel signal off This affects both the internal and external effects signals The large red LED lights to warn that the channel is muted Note...

Страница 22: ...cts Start with the channel FX sends turned fully off and the FX channel fader set to its normal 0 position Make sure that FX MUTE is not selected or the MIDI bypass turned on Choose one of the 16 effe...

Страница 23: ...reo chorus for guitars and keyboards FLANGE Classic stereo flange effect ROTARY SPK Rotary speaker emulation for organs and guitars PHASER Stereo phasing effect MIDI A standard 5 pin MIDI IN socket is...

Страница 24: ...ow then you are likely to hear the residual hiss and noise that is present in all electronic circuits If it is too high then there is a danger that it will try to exceed the maximum output and therefo...

Страница 25: ...e or post LR faders It affects both the analogue and digital SPDIF outputs In its normal up position the source follows the fader movements When the switch is pressed the LR faders can be used as the...

Страница 26: ...te if a fault is sensed and have a two second switch on delay and instant power off Constant power Most amplifiers produce their maximum output into 4 ohms with considerably less into 8 ohms The uniqu...

Страница 27: ...hy the parametric output EQ You are probably familiar with the 7 or 9 band graphic EQ used on traditional powered mixers These have a similar bell shaped response but set at fixed frequency points The...

Страница 28: ...of the connected equipment to match the normal 0dBu operating level of the console Impedance balanced outputs like differential electronic balanced drivers use a 3 wire connection and provide the bene...

Страница 29: ...s the signal path after the mix stage and before the LR fader With nothing plugged in the signal is routed through the switching contact within the socket The connection is unbalanced with both the in...

Страница 30: ...nbalanced inputs Operating level is 0dBu The output follows the panel AB source selection and EQ settings It does not break the signal path to the AB amplifiers AB AMP INPUT TRS inputs to plug externa...

Страница 31: ...trange phasing effects due to frequency cancellation If you hear this then check the wiring of the amps cables and speaker connections Speaker Impedance Live sound speakers are typically 4 ohm or 8 oh...

Страница 32: ...dent with moulded mains plug supplied AC mains 100 to 240V AC 50 60Hz internally wired Consumption 1600W max peak Mains fuse rating 100 240V AC T10A 250V 20mm A H part number AL3455 Manufacturer Schur...

Страница 33: ...AKER A B Speakon pin1 speaker positive pin1 speaker negative Minimum 4 ohms Do not bridge or common the pins Insert Connections Type Level Channel LR Unbalanced TRS tip send ring return 0dBu GAIN LM H...

Страница 34: ...You can now lift the panel away and place it inverted on the work surface 3 Unscrew the 6x 6B pan head front trim fixing screws shown in the diagram Take care to avoid damage to the faders The front t...

Страница 35: ...15 60Hz 15 FB1 O O FB2 6 O O AUX O O 6 6 O O FB2 O O O O AUX 250Hz 250Hz 250Hz 250Hz 12kHz LINE 10 10 30 10 10 30 10 10 10 30 10 30 10 10 30 10 30 10 O 6 R PAN O O L PAN PK PK O O L PAN 6 O O R L PAN...

Страница 36: ...36 PA CP User Guide Check out our Internet site http www allen heath com...

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