Technical information

Page 11
Micro-Tech 600/1200/2400 Power Amplifiers
Reference Manual
the rack so it blows outside air into the space between
the door and the front of the amplifiers. This will pressur-
ize the “chimney” behind the door (Figure 3.3, Option
1). The blower should not blow air into or take air out of
the space behind the amplifiers. For racks without a front
door, you can evacuate the rack by mounting the blower
at the top of the rack so air blows out the back (Figure
3.3, Option 2). You can estimate a rack’s required air
flow by adding each unit’s maximum air flow rating.
Each Micro-Tech 600 and 1200 can move 35 cubic feet
(1 cubic meter) of air per minute, and each Micro-Tech
2400 can move 45 cubic feet (1.3 cubic meters) of air
per minute. So if you put one of each in a rack, you
would need 115 cubic feet (3.2 cubic meters) of air flow
through the rack per minute under worst-case condi-
tions (35 cubic feet + 35 cubic feet + 45 cubic feet =
115 cubic feet).
Another cooling problem to consider is high ambient air
temperature. If the ambient air temperature is extremely
high, ODEP may reduce the output to protect the ampli-
fier even when it is receiving the maximum recom-
mended air flow. Under these unusual conditions, it may
be necessary to use air conditioning for supplemental
cooling. Air conditioning is rarely a necessity because
internal fans and rack-mounted blowers almost always
provide enough air flow for the most extreme conditions.
Still, air conditioning helps reduce the ambient tempera-
ture of the air flowing through the rack. If you plan to use
air conditioning, refer to Section 7 for information on cal-
culating the hourly thermal dissipation of your system.
3.3 Wiring
The following section describes common ways to install
your amplifier in a sound system. The input and output
terminals are located on the back panel. Please use
care when making connections, selecting signal
sources and controlling the output level. The load you
save may be your own! Crown assumes no liability for
damaged loads resulting from careless amplifier use or
deliberate overpowering.
CAUTION: When making or changing connections,
always disconnect the AC power and turn the level
controls off (fully counterclockwise). This is very im-
portant because it reduces the chance of loud blasts
that can cause loudspeaker damage.
Micro-Tech amplifiers may be operated in one of three
modes (Stereo, Bridge-Mono and Parallel-Mono) by
switching the stereo/mono switch on the back panel.
There are VERY IMPORTANT wiring differences among
these three modes which are discussed next.
3.3.1 Stereo (Two-Channel) Operation
In Stereo mode, installation is very intuitive: input chan-
nel 1 feeds output channel 1, and input channel 2 feeds
output channel 2. To put the amplifier into Stereo mode,
first turn the amplifier off, then slide the stereo/mono
switch to the center position, and properly connect the
output wiring as shown in Figure 3.4. Each channel has
a pair of binding posts for easy loudspeaker cable con-
nection. Observe correct polarity, and be very careful
not to short the two channels together.
Fig. 3.4 Stereo Wiring
STEREO MODE