DAPAudio D2250, Manual

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General Wiring Procedures
To take full advantage of the excellent signal to noise ratio and low distortion of consoles care must be taken to ensure
that incorrect installation and wiring does not degrade the performance of the desk. Hum, buzz , instability and Radio
Frequency interference can usually be traced to earth loops and inferior earthing systems. In some areas, especially
heavily industrial areas, the incoming mains earth will not be adequate and a separate technical earth for all the audio
equipment must be s upplied. However , check with your local electricity supply c ompany to ensure that safety
regulations are not infringed or negated.
The successful, hum free, installation of a system requires forethought ,and the establishment of a set of ground rules ,
which must be consistently adhered to at all stages of installation.
Initial Wiring Considerations
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For optimum performance,it is essential for the earthing system to be clean and noise free,as all signal are referenced
to this earth. A central point should be decided on for the main earth point system, and all earths should be 'star fed'
from this point. It is common electrical practice to ' daisy chain ' the earths to all electrical outlets but this method is
unsuitable for audio installations. The preferred method is to run an individual earth wire from each outlet, back to the
system star point to provide a safety earth screen reference for each of equipment.
A separate earth wire should also be run from each equipment rack and area to the star point . This may or may not be
used depending on circumstances, but it is easier to install in the first place, than later when problems arise.
The location of the star point should be convenient, easily accessible place preferably at the chassis of the console, or
in the main equipment rack.
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Install separate 'clean' and 'dirty' mains outlets, wired individually back to the incoming mains distribution box. Use
the 'clean' supply for all audio equipment and the 'dirty' supply for all lighting, vending machines etc. Never mix the
two systems.
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If necessary, to provide sufficient isolation from mains borne interference, install an isolating transformer.
This should be provided with a Faraday Shield which must be connected with earth.
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Never locate the incoming mains distribution box near audio equipment, especially tape recorders , which are very
sensitive to elector-magnetic fields.
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Ensure that all equipment racks are connected to earth, via a separate wire back to the star point.
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Equipment which has unbalanced inputs and outputs may need to be isolated from the rack to prevent earth loops.
8 BUS MIXING CONSOLE
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