Lab.gruppen LAB 500 - Manual (Page 4)

4
The rear
panel
Figure 2. Rear panel
Please refer to diagram on page 3
1. Speaker
connector
This type of speaker connector may be
unfamiliar to some users. A full description is found
in the operation section. (See page 6).
2. AC line cord (See page 5).
3. Input jack
Alternative to using input XLR or for linking
inputs with other amplifiers. (See page 5).
4. Input signal XLR (See page 5).
5. Phase reverse switch for channel B
For reversing the input signal phase of channel
B to allow bridged operation. (See page 7).
6. Link switch
Allows a single input to drive both channels
simultaneously. (See page 7).
7. Gain select switch
Allows amplifier gain to be switched between
29dB and its normal gain at 0.775mV input
sensitivity. (See page 7).
Installation
1. Mounting
The amplifier is two rack units high (2U) and will
mount in a standard EIA 19 inch rack. Amplifiers
may be stacked directly on top of each other. There
is no need for spacing between units. If it is the
intention to fill a rack with amplifiers, we
recommend racking is started from the bottom of
the rack. It is also recommended that rear supports
are used for amplifiers mounted in the middle of the
rack, especially if used as part of a portable system.
2. Cooling
Your amplifier uses forced air cooling system to
maintain a low and even operating temperature. All
Lab.gruppen amplifier, which are fan ventilated,
have front to rear cooling. There are several reasons
for this, one is that there's usually cooler air outside
the rack than inside and therefore the amplifiers can
run at higher continuos power levels without
thermal problems. Never try to reverse the air flow,
as the Intercooler® need a pressure chamber
between the fan and heat sink, and this only works
in one direction of the air flow (see Design features
on page 8).
Should a heat sink get too hot, its sensing circuit
will mute the hot channel. If the power supply
overheats, another sensing circuit will mute all
output channels, until it cools down to a safe
operating temperature.
Make sure that there is an adequate air supply in
front of the amplifier and that the rear of the
amplifier has sufficient space to allows the exhaust
to escape. If the amplifier is rack mounted, do not
use covers or doors on the front or rear of the rack.
For fixed installations with a central cooling
system, usually found in fixed installations with a
dedicated rack room, it may be necessary to
calculate the maximum heat emission. Refer to
Power consumption on page 5.
3. Operating voltage
A label just below the mains cable on the rear of
the amplifier indicates the AC mains voltage, for
which the amplifier is wired. Connect the power
cable only to the AC source referred to on the label.
The warranty will not cover damage caused by
connecting to the wrong type of AC mains.
For converting a 230 volt amplifier to 115 volt or
vice-versa, see Appendix A.
The amplifier is supplied with an approved European
AC line connector. If this connector is not
appropriate for your country, it can be cut off and
wired to a suitable connector in the following way :