Phoenix Gold pt1800 - Manual (Page 14)

pt1250 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 pt1250 requires two rack space units (3.5”) and a depth of 10.75” 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 pt1250 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. This
practice is recommended for all electronic instruments.
Thermal Considerations
When the pt1250 is used free-standing, no thermal considerations are necessary other than keeping the ventilation
holes open. If the amplifier is 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 pt1250 is fan cooled. The fan is internally mounted so that it draws air in from the rear and exhausts it out
the front. The pt1250 may be stacked directly on top of other amplifiers without spacer panels. If the pt1250 is used
with other amplifiers, ensure that the heat output from the other amplifiers doesn’t interfere with the ventilation of the pt1250
(or vice versa).
AC Power Considerations
Ensure that the pt1250 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 amplifier requires
the following average currents:
pt1250: 6.7 amps for 120V versions, 3.5 amps for 230V versions
Magnetic Leakage Considerations
The pt1250 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 20 for information on new input module)
The 1/4-inch phone jacks and XLR connectors for the input signal can be used with either unbalanced 2-conductor or
balanced 3-conductor cables. Use shielded coaxial cable to conduct the signal from the source (i.e. mixer, equalizer, CD
player) to the amplifier. In addition, a ground system strap allows isolating the amplifier circuit ground from the AC line
safety ground (green wire). Isolating the grounds may be necessary in some installations to break a ground loop.
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