Installation; Connections; Inputs; Speaker Outputs - Omnitronic SMA SERIES User Manual

6 INSTALLATION

This amplifier is built for 19" racks (483 mm). This rack use should be a double-door rack where front panel
and rear panel can be opened. The rack should be provided with a cooling fan. When mounting the amplifier
into the rack, please make sure that there is enough space around the device so that the heated air can be
passed on. Steady overheating will damage your device.
You can fix the amplifier with four screws M6 in the rack. If several devices are to be installed, make sure
that you leave 1 unit space between the devices.
Be careful when mounting the amplifier into the rack. Put the heaviest devices into the lower part of the rack.
Be aware that fastening the amplifier with four screws on the front panel is not enough. In order to ensure
safety, additional fastening by using ground and side bars is necessary.
If racks are to be transported or used for mobile use, additionally fasten the devices by connecting the rear
brackets with the side or ground bars of the rack. Thus, the amplifier cannot be pushed backwards. The front
panel alone is not designed to absorb acceleration forces occurring during transportation.

7 CONNECTIONS

All connections have to be made or changed only if the amplifier is switched off!

7.1 Inputs

Connect the output of a preamplifier or mixer to the balanced XLR inputs. The input signal should have line
level.
Information on choosing appropriate signal cables
Signal cables should be short and direct, since high frequencies will mostly be absorbed if cables are unnecessarily
long. Besides that a longer cable may lead to humming and noise trouble. If long cable runs are unavoidable, you
should use balanced cables.
• Occupation balanced XLR connection:
Balanced use with XLR connectors
2 1
3
Input
For unbalanced use pin 1 and pin 3 have to be bridged

7.2 Speaker outputs

In stereo mode, the amplifier can operate two speakers or two speaker groups. The amplifier can be
switched over to bridge operation to supply the double output power. Then it operates as 1-channel amplifier
and supplies power to one 8
are provided. For models SMA-1500, SMA-2000 the speakers can alternatively also be connected to
pairs of screw connectors. When using the Speaker jacks, turn each plug to the right until it locks into place.
For unlocking, pull the unlock button and turn the plug to the left. When interconnecting several speakers, it
is especially important to consider the correct connection to positive and negative contacts and that the
minimum total impedance is 4
• Occupation Speaker socket:
1
1 = Ground / Shield
2 = Hot (+)
3 = Cold (-)
speaker or one 8
for 2-channel operation and 8
2
3
Output
speaker group. For connecting speakers, Speaker jacks
for bridge operation.
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