ALLEN & HEATH Xone:32, Руководство пользователя

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10 XONE:32 User Guide
100 - 240V~
47-63Hz ~ 30W MAX
AVIS: RISQUE DE CHOC ELECTRIQUE - NE PAS OUVRIR.
Installation
Connecting Mains Power
Read the
SAFETY INSTRUCTIONS printed at the front of this
User Guide and on the rear panel. Check that the
correct mains lead with moulded plug has been
supplied with your console. The power supply
accepts 50/60Hz AC mains voltages within the range
100-240V without changing any fuses or settings.
It is standard practice to turn connected power
amplifiers down or off before switching the console
on or off. This prevents any audible switch-on
thumps. Ensure that the IEC mains plug is pressed
fully into the rear panel socket before switching on.
Earthing
The connection to earth (ground) in an audio system is important for two reasons:
1. SAFETY - To protect the operator from high voltage electric shock, and
2. AUDIO PERFORMANCE - To minimise the effect of earth (ground) loops which
result in audible hum and buzz, and to shield the audio signals 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
bodies, turntable chassis, equipment cases, 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. If problems are encountered with earth loops operate the audio ‘ground lift’ switches on
connected equipment accordingly, or disconnect the cable screens at one end, usually at the destination.
•
Make sure that turntables are correctly earthed A chassis earth terminal is provided on the console rear
panel to connect to turntable earth straps.
•
Deal with ground loops Should you experience hum or buzz caused by ground loops, check first that
each piece of equipment has its own separate path to ground. If so, operate ground 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. The console outputs are designed to operate at very low impedance to
minimise interference problems.
•
Use balanced connections for the microphone 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 drawing for
information 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. 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.