Introduction and Description
The AES-404 Digital Audio System comprises of a four input AES compatible switcher, two
output digital audio DA and digital to analog converter. The unit also has status and diagnostic
error indicators for troubleshooting. The AES-404 is intended for use for any application where it
is desired to switch AES formatted signals and for standard audio formats decode to analog L/R
output. Uses include studio or transmitter audio source switching or for virtually any digital
switching, distribution and/or D/A conversion application. As shipped from the factory the unit is
supplied with XLR balanced connectors. The front panel contains all of the buttons for controlling
the AES-404 including status indications and headphone confidence monitor. Remote control of
the unit is possible via a general purpose I/O or via RS232/485 connection. For unbalanced use
such as the 75 ohm unbalanced AES standard for digital audio transmission order part number
AES-404-75 which is supplied with BNC connector I/O for all digital inputs and outputs.
I.
Unpacking
Carefully inspect the unit after unpacking and make certain that no damage has occurred during
shipping. If damage is noted, contact the shipper immediately and file a claim for damages. Each
unit is carefully packed and carries full insurance against damage. Inspect the packing list and
make sure that the contents of the package match those described on the packing list.
II.
Installation and Connections
Select a space in suitable E.I.A. standard rack to locate the unit. Determine the local electrical
power supply voltage. As supplied from the factory, your AES-404 is setup for 100 – 240 V.A.C.
50 - 60 Hz. No external adjustment for local power standards is necessary if power available
conforms to the above rating. The AES-404 utilizes a switch mode power supply and
automatically adjusts for local power entry. Make connections to the unit following good
engineering practice. Supply power to the unit utilizing a three conductor grounded outlet. Do no
lift the electrical ground to the unit at the power receptacle as this will result in a safety hazard. In
the event of ground loops, lift the ground at the offending connection only. Make certain that the
unit is afforded proper ventilation in the area of the top cover vent.
A. Digital Interface
The AES-404 inputs are balanced XLR connections conforming to the AES standard. The unit
can also be supplied with BNC connectors for digital I/O. Each XLR connection is terminated at
110 ohms as per the standard. The balanced digital outputs are also XLR connections which
provide 110-ohm transformer coupled source impedance as per the AES standard. To unbalance
any input or output unbalanced termination adapters can be purchased from Broadcast Devices,
Inc. Order P/N 75 – XLRM for inputs and P/N 75-XLRF for output connections. All BDI adapters
utilize BNC female interface for application to 75 ohm BNC connectorized cabling if the unit has
been supplied with XLR connectors.
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