PSSO DDA-1700, Руководство пользователя

Страница: 22 / 28

5
5 5
5 Setup
5.1 Installation
This amplifier is built for 19" racks (483 mm) but can also be used as a tabletop unit. In order to ensure sufficient cooling
of the amplifier, air must always be able to flow freely through all air vents. For rack installation, the amplifier requires 2
U. If several units are to be installed, make sure that you leave 1 unit space between the devices. Insert the heaviest
units 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.
The hot air given off by the amplifier must be dissipated from the rack; otherwise heat will accumulate in the rack which
may not only damage the amplifier but also other units in the rack. In case of insufficient heat dissipation, install a
ventilation unit into the rack.
5.2 Signal connections
When setting up your amplifier, make connections as follows:
– Always make input connections prior to applying power to the amplifier.
–
Connect the outputs from the signal sources (e.g. preamplifier, mixer) to the XLR inputs (6)
–
For parallel connection of further PA amplifiers, the feed-through outputs can be used via the balanced XLR jacks (6) .
Connect the outputs to the inputs of the PA amplifiers.
–
Connect the speakers with a two-pole Speaker jacks. When connecting multiple speakers, always observe the correct
the polarity and make sure that the total impedance is at least 2 Ω in multi-channel mode or 4 Ω in bridged mode.
–
Finally connect the amplifier to the mains with the mains cable.
–
Always make sure that your power amplifiers are the last item turned on and the first turned off.
5.2.1 Stereo operation
In stereo mode, the amplifier can operate four speakers or four speaker groups independently of each other. The highest
output power during is achieved by connecting 4 Ω speakers. With 8 Ω speakers the output power will be slightly
reduced. For this operating mode, set the
MODE switch to the STERERO position.
5.2.2 Parallel operation
In parallel operation, channels 1 and 2 receive the same input signal. A signal at the input of channel 2 is ignored. The
volume is separately adjusted for all outputs. This way, PA amplification can provided e.g. for several rooms using the
same mono signal while adjusting the volume independently. For this operating mode, set the
MODE switch to the PAR
position.
5.2.3 Bridge operation
In bridge mode, channels 1 and 2 are bridged and therefore provide higher power than a single channel. Thus, the
voltage at the output of channel 1 is doubled and subsequently the output impedance. A signal at the input of channel 2
is ignored. The volume is adjusted together for both outputs with the control of channel 1. For this operating mode, set
the
MODE switch to the BRI position.
22