Radio Shack 32-2055 User Manual
250-Watt • Stereo
32-2055
PA Amplifier
Thank you for purchasing your 250-Watt • Stereo PA Amplifier from
RadioShack. This PA gives you the versatility and power you need in a
professional sound system. Its wide frequency response easily handles
amplification of voice and music. Use it anywhere you need to deliver
special announcements with excellent sound. It is perfect for meeting halls,
auditoriums, sporting events, schools, or in the office for paging systems.
With a bridged speaker connection, the amplifier can produce up to 350
watts of clean, powerful sound with minimum distortion.
What’s Included
PA Amplifier
User’s Guide
Quick Start Guide
www.radioshack.com
C
ontents
Important Safety Instructions ............................................................................3
About Your Amplifier......................................................................... 6
Amplifier Features.............................................................................................. 6
Amplifier Setup............................................................................................ 10
Getting Started ................................................................................................. 10
Select a Location................................................................................................... 10
Preset the Controls...............................................................................................10
Preset the Audio Input Source...........................................................................10
Presetting the Amplifier .....................................................................................10
Connecting Your Amplifier................................................................................ 11
Connecting Input Sources....................................................................................11
Connecting Microphones ....................................................................................11
Connecting a Turntable........................................................................................ 12
Connecting an Auxiliary Sound Source ..............................................................12
Connecting the MIX BUS Jack............................................................................. 12
Connecting an Equalizer......................................................................................13
Connecting Speakers ...........................................................................................13
Determining Total Speaker Impedance............................................................14
Preparing the Speaker Wires ............................................................................. 14
Connecting Two Speakers in Series .................................................................. 15
Connecting Two Speakers in Parallel ................................................................15
Unbridged Connection ......................................................................................16
Bridged Connection ........................................................................................... 16
Connecting Power ................................................................................................ 17
Operating Your Amplifier............................................................................. 18
Beginning Steps ......................................................................................................18
Monitoring Sound Sources .................................................................................. 18
Listening Safely ..................................................................................................... 18
Using the Feedback Filter ....................................................................................19
Using the Level Meters and Clipping Indicator .................................................19
Using Speaker A/B................................................................................................ 19
Additional Information................................................................................. 20
Care and Service .............................................................................................. 20
Replacing the Fuse ............................................................................................... 20
Troubleshooting.................................................................................................... 21
Specifications ........................................................................................................22
Do More with Your Amplifier...........................................................................23
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Important Safety Instructions
1. Read all safety and operating instructions before the appliance is used.
2. Keep all safety and operating instructions for future reference.
3. Follow all warnings on the appliance and in the operating instructions.
4. Unplug this appliance from the wall outlet before cleaning. Use only a damp
cloth for cleaning. Do not use liquid or aerosol cleaners.
5. Do not use this appliance near water (for example, near a bathtub,
washbowl, kitchen sink, or laundry tub; in a wet basement; or near a
swimming pool).
6. Do not place this appliance on an unstable cart, stand, tripod, bracket,
or table. The appliance may fall, causing serious injury to a child or adult,
and serious damage to the appliance. Use only with a cart, stand, tripod,
bracket, or table recommended by the manufacturer or sold with the
appliance. Follow the manufacturer’s instructions for mounting, and use a
recommended mounting accessory.
7. Slots and openings in the cabinet provide ventilation, ensure reliable
operation, and protect from overheating. Do not block or cover these
openings, and do not place the appliance on a bed, sofa, rug, or other
similar surface. Do not place the appliance in a built-in installation such as
a bookcase or rack unless it provides proper ventilation as specified by the
manufacturer.
8. Keep appliance away from heat sources such as radiators, heat registers,
stoves, or other appliances (including amplifiers) that produce heat.
9. Operate this appliance using only the power source indicated on its marking
label. If you are not sure of your home’s power type, consult your appliance
dealer or local power company.
10. This device is equipped with a three-wire grounding-type plug, a plug
having a third (grounding) pin. This plug will only fit into a grounding-type
power outlet. This is a safety feature. If you are unable to insert the plug into
the outlet, contact your electrician to replace your obsolete outlet. Do not
defeat the safety purpose of the grounding-type plug.
11. Route power-supply cords so they are not likely to be walked on or pinched
by items placed on or against them, paying particular attention to cords
at plugs, convenience receptacles, and the point where they exit from the
appliance.
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12. Clean only as recommended by the manufacturer.
13. An outside antenna system should not be located in the vicinity of overhead
power lines or other electric light or power circuits, or where it can fall into
such power lines or circuits. When installing an outside antenna system,
extreme care should be taken to keep from touching such power lines or
circuits as contact with them might be fatal.
14. Unplug the power cord from the outlet when you know that you will not be
using the appliance for a long period of time.
15. Do not overload wall outlets, extension cords, or integral convenience
receptacles, as this can result in a risk of fire or electric shock.
16. Never push objects of any kind into this appliance through openings, as
they may touch dangerous voltage points or short out parts that could result
in a fire or electric shock. Never spill liquid of any kind on the appliance.
17. Move appliance and cart combinations with care. Quick stops, excessive
force, and uneven surfaces may cause the appliance and cart combination
to overturn.
18. Unplug this appliance from the wall outlet and refer servicing to qualified
service personnel under the following conditions:
• When the power-supply cord or plug is damaged.
• If liquid has been spilled or objects have fallen into the appliance.
• If the appliance has been exposed to rain or water.
• If the appliance does not operate normally by following the operating
instructions. Adjust only those controls that are covered by the operating
instructions, as an improper adjustment of other controls may result in
damage and will often require extensive work by a qualified technician to
restore the appliance to normal operation.
• If the appliance has been dropped or damaged in any way.
• When the appliance exhibits a distinct change in performance.
19. Do not attempt to service this appliance yourself, as opening or removing
covers may expose you to dangerous voltage or other hazards. Refer all
servicing to qualified service personnel.
20. When replacement parts are required, be sure the service technician has
used replacement parts specified by the manufacturer or have the same
characteristics as the original part. Unauthorized substitutions may result in
fire, electric shock, or other hazards.
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21. Upon completion of any service or repairs to this appliance, ask the service
technician to perform safety checks to determine that the appliance is in
proper operating condition.
22. For added protection for this product during a lightning storm, unplug
it from the wall outlet. This will prevent damage to the product due to
lightning and power line surges.
23. Only use attachments recommended by the product manufacturer.
24. The product should be mounted to a wall or ceiling only as recommended
by the manufacturer.
25. Overloading — Do not overload wall outlets, extension cords, or integral
convenience receptacles, as this can result in a risk of fire or electric shock.
WARNING: To reduce the risk of fire or shock hazard, do not expose
this product to rain or moisture.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT
REMOVE THE COVER OR BACK. NO USER-SERVICEABLE PARTS
INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL.
This symbol is intended to alert you to the presence of uninsulated dangerous voltage within the product’s enclosure
that might be of sufficient magnitude to constitute a risk of
electric shock. Do not open the product’s case.
This symbol is intended to inform you that important
operating and maintenance instructions are included in the
literature accompanying this product.
5
About Your Amplifier
Amplifier Features
Illuminated Power
Switch
Lights up when you
turn on the switch.
PHONES Jack
Connect
headphones
here.
Output Power
Level Indicators
Indicates the total
stereo output
power level.
A/B Speaker Switch
Select the speakers you want
to use with the amplifier in
Channel A, Channel B, or
both (for use with 8 ohm
speakers only).
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MIC 1, MIC 2, MIC 3
Adjust volume for the
connected microphones.
CD/AUX
Adjust volume of
CD or auxiliary
sound source.
About Your Amplifier
CLIPPING Indicator
Lights up to remind
you to reduce volume
when the amplifier
output is too high.
PROTECTION Indicator
Lights up when the
amplifier overheats or
if a shorted load occurs
on the amplifier output.
The amplifier resets itself
when the problem is
corrected.
MIC 4/PHONO
Adjust volume
of connected
microphone (MIC 4)
or turntable.
FEEDBACK FILTER
Turn to control audio
feedback.
Volume Control:
Left/Right speakers
Turn to regulate volume of
left and right speakers.
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About Your Amplifier
XLR Balanced
Microphone Inputs
Connect up to four
high impedance
microphones to your
amplifier.
Cooling Fan
Automatically activated
whenever the amplifier
is turned on. This air
cooling system rapidly
disperses interior heat
to reduce operating
temperature.
¼” Stereo Input
Jacks
Connect stereo
input sources (CD
or DVD player, TV,
etc.) here using a
¼-inch (balanced)
audio cable.
¼” Unbalanced
Microphone Inputs
Connect up to four
microphones to your
amplifier using a ¼”
unbalanced cable, for
left and right mono
sound.
MIC 4/PHONO
Switch
Select MIC 4 or
PHONO input.
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Phono Input Jacks
Connect your turntable here.
MIX BUS Jack
Connect an extra amplifier if you
have multiple audio sources.
CD/AUX Jack
Connect any high-level sound
source for music or special effects.
EQ IN/OUT Jacks
Connect an equalizer or other
external processor.
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