Installation
Location and General Precautions
Observe the following precautions when choosing a location for your amplifier.
A. Do not expose the unit to rain or moisture. If a fluid or foreign object should enter the unit, disconnect
the power plug and contact an authorized dealer or service center. Do not pull out the plug by pulling on the
cord; grasp the plug firmly.
B. Protect from heat and allow adequate ventilation. Place away from direct sources of heat, such as heating
vents and radiators. All components produce some heat during operation, so make sure that the ventilation
holes are not covered and that air is allowed to circulate freely behind, beside and above the unit. Excessive
heat is the single greatest source of both short-term and long-term component failure.
Mechanical Considerations
The PX850 and PX1450 require three rack space units (5.25”) and a depth of 15.38” inside the rack, including the rear
supports. Secure the unit mechanically using four screws with washers to prevent marring the front panel. Neoprene rubber
washers are a good choice because they grip the screw head and prevent them from backing out when vibrated or transported.
Rear Support for Road Applications
If the PX amplifier is rack-mounted and the rack is transported, mechanical support for the rear of the amplifier is
required. This could take the form of a shelf across the rear of the amplifier or brackets that engage the rear of the unit.
Rear support is recommended in all PX amplifier installations.
Thermal Considerations
When the PX850 or PX1450 is used free-standing, no thermal considerations are necessary other than keeping the
ventilation holes open. If the amplifiers are rack-mounted, ensure that adequate ventilation exists in front of and behind
the amplifier. When several amplifiers are mounted together in a rack, you may need to provide air inlets from the
outside of the rack. The PX amplifiers are fan cooled. The fan is internally mounted so that it draws air from the rear
and exhausts it out the front. The PX amplifiers may be stacked directly on top of each other without spacer panels. If
the amplifiers are used with other amplifiers, ensure that the heat output from the other amplifiers doesn’t interfere with
the ventilation of the PX amplifier (or vice versa).
AC Power Considerations
Ensure that the PX amplifier is plugged into an outlet capable of supplying the correct voltage specified for your model
and enough current to allow full-power operation of all the amplifiers plugged into it. The current demand of a power
amplifier varies depending on several factors, including the impedance of the load, the output level of the amplifier,
and the crest factor and duty cycle of the program material. Under typical conditions reproducing rock music, with both
channels driven into a 4 ohm load to the point where musical peaks are just at the clipping point, the amplifiers require
the following average currents:
PX850: 6.0 amps for 120V versions, 3.2 amps for 230V versions
PX1450: 8.0 amps for 120V versions, 4.2 amps for 230V versions
Magnetic Leakage Considerations
The PX amplifiers may be mounted without concern for magnetic flux leakage, within the confines of common sense. For
example, it’s not a good idea to mount any power amplifier near a microphone input transformer or magnetic storage media.
Input Wiring
(see page 17 for recommended Carver Professional Accessories)
Standard Version
The Neutrik™ combi connectors will accept either 1/4” phone jacks or XLR connectors. The input signal can be used
with either unbalanced shielded single conductor or balanced shielded 2 conductor cables. Use shielded coaxial cable
to conduct the signal from the source (i.e. mixer, equalizer, CD player) to the amplifier.
9
Figure A
10
Figure B
Figure C
Figure D
Figure E
Figure F
For balanced operation:
1/4-inch phone jack: Use a 3-conductor TRS (tip-ring-sleeve) 1/4” phone plug. The tip of the plug carries
the “+” (high, noninverting) side of the signal, the ring carries the “-” (low, inverting) side of the signal and
the sleeve is ground (see Figure A ) .
XLR: Use a male XLR connector. Pin 2 carries the “+” (high, non-inverting) side of the signal, Pin 3 carries
the “-” (low, inverting) side of the signal, and Pin 1 is ground (see Figure B).
For unbalanced operation:
1/4-inch phone plug: Use a 2-conductor (Tip-Sleeve) 1/4” phone plug. The tip of the plug carries the signal and
the sleeve is ground. The ring connection in the jack is automatically grounded by the sleeve (see Figure C).
XLR: Pin 2 carries the hot side of the signal, and Pin 1 is ground. Short Pin 3 to Pin 1 in order to reference the input
differential amplifier for the correct gain (see Figure D).
BR Version
For balanced operation:
Use shielded twisted pair balanced line type cable with crimp-on or solder type 8mm. spade terminals. For either channel
connect the “+” (high, non-inverting) side of the signal to the terminal labeled “+” on the Barrier Strip. Connect the “–”
( l o w, inverting) side to the “–” terminal. Connect the shield to ground. (See figure E).
N O T E: confirm which wires are “+” and “–” from the source unit. Refer to the 1/4” plug and XLR instructions for
proper configuration if these plugs are used at the source unit.
For unbalanced operation:
Use shielded single conductor coax type cable or twisted pair balanced line type cable with crimp on or solder type spade
terminals. Connect the hot side of the signal to the terminal labeled “+” on the barrier strip. Connect the shield to
“ground” a n d to the “–” terminal. (see Figure F)
NOTE: The gain remains the same regardless of whether the input is balanced or unbalanced
Input Sensitivity
The input sensitivity of the amplifier is set at the factory to 1.5V
R M S
for rated output. The input sensitivity can be changed to
0 . 7 7 5 V
R M S
, or +28dB fixed gain by using the switch on the back panel.
