10
– CXA160 / CXA80
5. THERMAL CONSIDERATIONS
The power amplifier within the unit is convection cooled
rather than fan cooled. Heat is drawn away from the
amplifier by the heatsink and radiated through the cooling
vents in the top and bottom cover.
When installing, be sure to allow sufficient air space
around the top and rear of the amplifier to allow
adequate cooling for the heatsink. Leave at least one rack
space above and below, and at least 6 inches behind the
chassis to allow proper ventilation.
If the amplifier should overheat, a thermal switch turns
off the power amplifier, allowing the heatsinks to cool
down. Once the amplifier has cooled to a safe operating
temperature, the thermal switch resets and reactivates
the amplifier. If this should occur, identify the cause of the
problem and take corrective action. For example:
• Provide better ventilation,
• Install a fan in the rack to move more air,
• Make sure the amplifier is not overloaded with too
low of a load impedance or by a short circuit on the
speaker line.
RACK MOUNTING
The front panel rack holes allows the unit to be fitted
within a standard 19" rack.
The unit still needs to be supported underneath, due to the
weight of the power and output transformers.
6. CONNECTIONS
The Input and Priority Input use a dual-purpose input
connector which can accept XLR and 1/4" TRS and TS plugs.
XLR Connectors
Inputs 1 and 2 can accept 3-pin male XLR connectors, wired
as follows:
XLR Balanced Wiring
Pin 1 = Shield
Pin 2 = Hot (+)
Pin 3 = Cold (–)
1/4" TRS Phone Plugs and Jacks
“TRS” stands for Tip-Ring-Sleeve, the three connections
available on a stereo 1/4" or balanced phone jack or plug.
TRS jacks and plugs are used for balanced signals and
stereo headphones:
1/4" TRS Balanced Mono wiring:
Sleeve = Shield
Tip = Hot (+)
Ring = Cold (–)
1/4" TS Phone Plugs and Jacks
“TS” stands for Tip-Sleeve, the two connections available
on a mono 1/4" phone jack or plug. They are used for
unbalanced signals.
1/4" TS Unbalanced Wiring:
Sleeve = Shield
Tip = Hot (+)
Phoenix-type Connectors
These connectors use small screws to clamp the wires in
place. They can be balanced, using three conductor wiring,
or unbalanced using two-conductor wiring and a small
wiring link joining the ground and negative connector.
Balanced
Unbalanced
1
2
3
1
2
3
2
2
3
1
1
SHIELD
COLD
HOT
SHIELD
COLD
HOT
3
SHIELD
COLD
HOT
3
2
1
SLEEVE
TIP
TIP
SLEEVE
TIP
SLEEVE
SLEEVE
TIP
SLEEVE
TIP
RING
RING
TIP
SLEEVE
RING
