Manual
20 DL251 Audio System I/O
MUSIC Group IP Limited
DL251/DL252 Getting Started
2. Getting Started
This section shows you how to unpack, install, connect up, 
switch on and configure the DL251/DL252 unit.
This equipment is supplied by a mains voltage that can 
cause electric shock injury.
Before installing, setting up or operating this equipment, 
make sure that you have read and fully understand all of 
this section and the “Important safety instructions” at the 
front of this manual.
Refer to additional safety information on the top cover of 
the unit.
Unpacking
Carefully unpack your DL251/DL252 equipment package.
Then, inspect the DL251/DL252 unit carefully for any signs of 
damage that may have occurred during transit and notify the 
courier immediately if you discover any.
Check the contents of your DL251/DL252 equipment package. 
If there are any parts missing, incorrect or faulty, please 
contact your local distributor or Midas at the address at the 
front of this manual.
Please retain the original packing in case you should need to 
return the equipment to the manufacturer or supplier, or 
transport or ship the unit later.
Installation
Before installing and operating this equipment, make sure it is 
correctly connected to the protective earth conductor of the 
mains voltage supply socket outlet through each mains lead.
Ideally a cool area is preferred, away from power distribution 
equipment or other potential sources of interference.
Do not install the equipment in places of poor ventilation.
Do not install this equipment in a location subjected to 
excessive heat, dust or mechanical vibration. Allow for 
adequate ventilation around the equipment, making sure that 
its fans and vents are not obstructed. Whenever possible, 
keep the equipment out of direct sunlight.
Mount in rack only.
Power
Both supply cords must be unplugged to ensure 
complete de-energisation of the unit.
The internal power supplies are of the switch mode type that 
automatically senses the incoming mains voltage and will work 
where the nominal voltage is in the range 100VAC to 240VAC.
Two mains inlets are provided on the rear panel. The correct 
leads for connection in the area to which the unit was shipped 
are supplied with the unit. The equipment should only be 
plugged into the mains outlets using the supplied leads.
Each mains inlet must be sourced from its own separate 
wall-mounted mains outlet socket. Otherwise, their mains 
sources must be suitably distributed so as to meet local safety 
regulations.
Make sure the Volex locking type plugs, fitted on each supplied 
mains cable, are securely fitted to the mains IEC connectors 
on the unit. When fitted properly the Volex plug locks into 
place, preventing it from working loose, or being inadvertently 
knocked loose or pulled out. When fitting or removing a Volex 
plug, always hold the plug itself and never use the cable, as 
this may damage it. Never insert or remove an electric plug 
with wet hands.
When switching the unit on/off, switch the mains power 
switches on/off one at a time.  Do not switch them on/off 
simultaneously.
Handling the equipment
When lifting or moving the equipment, always take its size and 
weight into consideration.
Completely isolate the equipment electrically and disconnect 
all cables from the equipment before moving it.
Do not insert your fingers or hands in any gaps or openings on 
the equipment, for example, vents.
Electric fields
In accordance with Part 15 of the FCC Rules & Regulations, 
“… changes or modifications not expressly approved by the 
party responsible for compliance could void the user's 
authority to operate the equipment.”
Should this product be used in an electromagnetic field that is 
amplitude modulated by an audio frequency signal (20Hz to 
20kHz), the signal to noise ratio may be degraded. 
Degradation of up to 60dB at a frequency corresponding to the 
modulation signal may be experienced under extreme 
conditions (3V/m, 90% modulation).
Connecting up
Connect up the rear panel of your unit as follows (see 
Chapter 5. Connections on page 34):
• Inputs — connect your XLR mic/line inputs (up to 48 on 
DL251 and 16 on DL252).
• Outputs — connect your XLR line outputs (up to 16 on 
DL251 and 48 on DL252).
• AES50 audio — connect the AES50 audio sockets to the 
console/snake.
• Ethernet — connect the Ethernet control socket to an 
external computer for remote control when used in a snake 
configuration if required.
• MIDI — connect the three MIDI 5-pin DIN connectors to the 
MIDI equipment if required. (For use with Midas consoles 
only.)
• Mains power — connect the dual redundant IEC 
connectors of the mains cables into the rear of the unit and 
then plug them into separate mains power outlets (see 
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