Radio Shack 04A00, 32-2004 User Manual

250-Watt Stereo PA Amplifier
Owner’s Manual
Please read before using this equipment.
ˆ
Contents .................................................................................................................................. 2
Features .................................................................................................................................. 3
Preparation ............................................................................................................................. 4
Presetting the Controls ...................................................................................................... 4
Presetting Audio Input Devices .................................................................................. 4
Presetting the Amplifier .............................................................................................. 4
Mounting the Amplifier ...................................................................................................... 4
Placing the Speakers ........................................................................................................ 4
Connections ............................................................................................................................ 5
Connecting an Input Source .............................................................................................. 5
Unbridged Connection ............................................................................................... 5
Bridged Connection ................................................................................................... 5
Grounding the Input Source .............................................................................................. 6
Connecting Speakers ........................................................................................................ 6
Preparing the Speaker Wires ..................................................................................... 6
Unbridged Connection ............................................................................................... 6
Bridged Connection ................................................................................................... 7
Using the Switched AC Outlet ........................................................................................... 7
Connecting Power ............................................................................................................. 7
Using Your Amplifier .............................................................................................................. 8
Using the Meters/METER RANGE .................................................................................... 8
CLIP Indicator ................................ ...................................................................... ............. 8
Using SPEAKER A/B ........................................................................................................ 8
Monitoring the Sound Sources .......................................................................................... 8
Listening Safely ......................................................................................................... 9
Care ......................................................................................................................................... 9
Replacing the Fuse .............................................................................. ............................. 9
The FCC Wants You to Know .............................................................................................. 10
Specifications ....................................................................................................................... 11
©
1998, 2000 Tandy Corporation.
RadioShack is a registered trademark used by Tandy Corporation.
2
All Rights Reserved.
Contents
ˆ
Features
Your Public Address Amplifier 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 in meeting halls and audi­toriums, at sports events, in schools, and in the office for paging systems — anywhere you need to deliver special announcements with excellent sound.
The amplifier (if bridged) produces up to 350 watts of clean, powerful sound with minimum distortion.
Your amplifier includes these features:
10–50000 Hz Frequency Response Built-In Cooling Fan
amplifier by reducing its internal tempera­ture.
Two Mounting Options
the amplifier in a standard-sized audio equip­ment rack or on a desk, shelf, or table.
2 Lighted VU Meters
fier’s output for each channel in decibels.
Left and Right Output Level Gain Controls
— let you adjust the overall sound level on the left and right channels.
Clipping Indicator
source signal overdrives the amplifier.
Phones Jack
phones so you can listen privately.
Bridging Capability
amplifier’s two channels and use the amplifi­er with only one channel, producing a total of 350 watts.
Meter Range Select Switch
trol the meter’s sensitivity.
— lets you connect head-
— helps protect the
— you can mount
— measure the ampli-
— lights if a sound
— you can combine the
— lets you con-
Input Jacks
audio input sources for music and special ef­fects.
A/B SPEAKER
speakers you want to use with the amplifier.
STEREO/MONO
output type; stereo or mono (bridged).
Binding Post Terminals
connect wires directly to the amplifier.
Switched AC Outlet
devices by plugging them into the back of the amplifier.
WARNING
shock hazard, do not expose this product to rain or moisture.
CAUTION
ELECTRIC SHOCK, DO NOT REMOVE COVER OR BACK. NO USER-SERVICE­ABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL.
!
—let you connect a variety of
Switches
Switch
: To reduce the risk of fire or
CAUTION
RISK OF ELECTRIC SHOCK.
: TO REDUCE THE RISK OF
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.
— let you select the
— lets you select the
— let you easily
— lets you power other
DO NOT OPEN.
!
Features
3
ˆ
Preparation
PRESETTING THE CONTROLS
Before you begin making connections or us­ing your amplifier, preset the audio input source’s and the amplifier’s controls to avoid overdriving a channel or producing sudden unexpected loud sounds.
Warning:
set the audio input device’s and amplifier’s controls as indicated in the following sec­tions. After you turn on the amplifier or change the program source, adjust the con­trols to a comfortable listening level.
Presetting Audio Input Devices
Always set the power control for an audio mixer or preamplifier you connect to the am­plifier to OFF.
Presetting the Amplifier
Set the amplifier’s controls as follows:
POWER SPEAKER A/B LEFT and RIGHT MIN METER RANGE
To prevent possible hearing loss,
Control Setting
Out Out
Out
MOUNTING THE AMPLIFIER
You can mount the amplifier in a standard­sized audio equipment rack or on a desk, shelf, or table. Before you use your amplifier, be sure you place it in a location with ade­quate ventilation. Do not put it on thick car­peting (which can restrict air flow) or near a heat source such as a heat vent or radiator (which can cause it to overheat).
To mount the amplifier on a standard-sized audio equipment rack, drive and tightly se­cure mounting screws (not supplied) through the mounting holes.
PLACING THE SPEAKERS
Speaker placement depends on your room’s size and arrangement. We recommend you play a wide-range recording and experiment with speaker placement until you find the lo­cations that result in the best sound. For the best results, point the speakers toward the audience (especially if the speakers are far apart) so the coverage areas overlap to pre­vent dead spots (areas not covered by the speakers’ sound). Position the speakers slightly above the level of the listeners’ heads (see “Connecting Speakers” on Page 6).
4
Preparation
The following drawings show recommended speaker placements for typical, narrow, and wide sound coverage.
Typical Coverage
ˆ
Connections
Wide Area CoverageNarrow Coverage
(two speakers)(single speaker)
CONNECTING AN INPUT SOURCE
You can connect a component such as an audio mixer or preamplifier to the inputs on the back of your amplifier. Each input (la-
INPUT
beled anced and unbalanced jack. You need a shielded cable with a phono plug to connect to an unbalanced jack or a cable with a phono-type plug to connect to a balanced jack. To prevent hum and oth­er noise, use low-capacitance shielded ca­ble. Your local RadioShack store carries a wide selection of audio components, parts, and cables.
Note:
If you are using the
you must connect an audio mixer or pre-am­plifier to this amplifier.
Cautions:
• You can connect audio mixers or pream-
• Before you make any connections, be
plifiers to either the balanced or unbal­anced jacks. Do not connect input sources to both jacks at the same time.
POWER
sure
INPUT MONO
and
on the front of the amplifier
) has a bal-
1
/4-inch (6.35-mm)
MIC
level inputs,
is off and the AC power cord is not plugged in.
Unbridged Connection
If you are connecting more than one speaker on the same channel (unbridged connec­tion), connect your audio mixer’s or preampli­fier’s left and right output jacks to the
R
INPUT L
and fier. Then, make sure back of the amplifier is set to
jacks on the back of the ampli-
STEREO/MONO
STEREO
INPUT
on the .
Bridged Connection
If you are connecting high-power speakers that can handle a power output of 350 watts (bridged connection), connect your audio mixer’s or preamplifier’s output jack to the
PUT MONO
INPUT L
or
jack on the back of the
IN-
Connections
5
amplifier. Then, make sure
STEREO/MONO
on the back of the amplifier is set to
MONO
speakers, use this table to determine the wire length and choose the appropriate
.
gauge.
GROUNDING THE INPUT SOURCE
To avoid a low frequency hum, connect your audio mixer’s or preamplifier’s ground wire
GND
(usually black or green) to the
terminal
on the back of the amplifier.
CONNECTING SPEAKERS
You can connect one or more 4-, 8-, or 16­ohm speakers to the amplifier. You can also bridge the amplifier’s channels.
A
The amplifier has two channels: you connect two pairs of speakers, follow these guidelines:
• Speakers connected to the same chan-
A
or B) are part of a pair and must
nel ( be of the same impedance.
• Speakers connected to different chan-
A
or B) are not part of a pair and
nels ( can be different impedances.
Most speaker terminals are color-coded or have a mark that indicates the terminal’s po­larity. Usually, terminals with positive polarity are red or have a plus symbol (+), and termi­nals with negative polarity are black or have a minus symbol (–). Phasing is correct when you connect + to + and – to –.
and B. If
Wire Length Wire Gauge
25 feet or less 18 gauge Over 25 feet 16 gauge
To prepare the speaker wire, remove about 1 inch of insulation from the end of the speaker wire you are connecting to the amplifier. Then twist the exposed wire to secure all of the wire strands.
Split strands about 4”
Wire Strands
1"
Unbridged Connection
Use this connection if you are connecting more than one speaker on the same channel or if you do not have high-power speakers.
1. Connect the speaker wires to the corre­sponding left and right speaker’s positive (+) and negative (–) ter­minals.
2. Connect the other end of the left and right speaker’s positive (+) and negative (–) wires to the amplifier’s correspond-
SPEAKERS LEFT
ing
and
SPEAKERS
Preparing the Speaker Wires
Use the shortest length of wire possible to connect the speakers. After placing the
6
Connections
RIGHT
terminals for each channel (as
shown here).
SPEAKERS RIGHT
here).
terminals (as shown
To connect the speaker wires to the amplifier, turn the knob on the terminal counter­clockwise until it stops, insert the bare wire inside the space between the knob and the ampli­fier, then turn the knob clockwise until it stops to secure it.
3. Make sure
REO
.
STEREO/MONO
is set to
STE-
Bridged Connection
Use this connection only if you have high­power speakers that can handle a power out­put of 350 watts.
Important:
connect any speaker wires to the black
SPEAKERS
1. Connect the speaker wires to the
2. Connect the other end of the speaker’s
For a bridged connection, do not terminals.
speaker’s positive (+) and negative (–) terminals.
positive (+) and negative (–) wires to the amplifier’s red
SPEAKERS LEFT
and
Note:
SPEAKERS RIGHT (+)
on the amplfier is used as a negative (–) termi­nal for a bridged connection.
3. Make sure
MONO
.
STEREO/MONO
is set to
USING THE SWITCHED AC OUTLET
The amplifier’s switched AC outlet provides a source of 120 V, 60 Hz power for audio equipment you connect to it.
POWER
on the amplifier turns both the amplifier and th e au­dio equipment connected to this outlet on or off.
CONNECTING POWER
To connect the amplifier to power, plug the attached power cord into a standard AC out­let.
Your amplifier’s fuse (located on the amplifi­er’s back panel) protects the amplifier from voltage surges. If the amplifier does not work when you press
POWER
is blown, see “Replacing the Fuse” on Page 9 to replace it.
, check the fuse. If it
Connections
7
ˆ
Using Y our Amplifier
1. Start the input sound source.
2. Make sure of the amplifier are set to
3. Press
4. One at a time, adjust the desired volume level.
Turn increase or counterclockwise to decrease the corresponding left and right output power. To get the best per­formance with the least sound distortion, always adjust meter’s pointer does not continuously swing to the extreme right.
5. When you finish, press off the amplifier.
LEFT
POWER
LEFT
and
to turn on the amplifier.
and
LEFT
RIGHT
MIN
LEFT
RIGHT
clockwise to
and
POWER
on the front
.
RIGHT
and
RIGHT
so the
to turn
to
USING THE METERS/METER RANGE
The position of the pointers on both of the amplifier’s meters indicate the output power. Built-in lamps light to make the meters easy to see in dark areas.
METER RANGE
meters. When output power is too strong, a meter’s needle might continuously swing to the extreme right and damage or reduce the accuracy of the meter.
controls the sensitivity of both
nal exceeds the output power level you set
LEFT
using ble damage to the amplifier. If this happens, reduce the output level of the connected sound source or dicator flickers only at peak volume levels.
and
RIGHT
, warning you of possi-
LEFT
and
RIGHT
until the in-
USING SPEAKER A/B
Press in front of the amplifier for the channel you want to listen to. Or, press in
SPEAKER B
ers.
Caution:
to the amplifier, to avoid damage do not set both position.
SPEAKER A
to listen to all connected speak-
If you connected 4 ohm speakers
SPEAKER A
and
SPEAKER B
or
SPEAKER A
SPEAKER B
on the
and
to the in
MONITORING THE SOUND SOURCES
To monitor the sound sources directly from the amplifier, connect a pair of mono or ste­reo headphones with a 1/4-inch (6.35-mm) plug into the amplifier. Using headphones lets you easily check and adjust the sound source’s bal­ance.
Note:
wide selection of headphones.
PHONES
Your local RadioShack store carries a
jack on the front of the
If the meter’s needle continuously swings to the extreme right, press the out position to maintain a 0 dB gain for the meter. Or, press position to allow a 20 dB gain.
METER RANGE
METER RANGE
to the in
CLIP INDICATOR
The CLIP indicator on the front of the amplifi­er lights steadily when a sound source’s sig-
8
Using Your Amplifier
to
Listening Safely
To protect your hearing, follow these guide­lines when you use headphones.
• Set the volume to the lowest setting
before you begin listening. After you begin listening, adjust the volume to a comfortable level.
ˆ
Care
• Do not listen at extremely high volume levels. Extended high-volume listening can lead to permanent hearing loss.
• Once you set the volume, do not increase it. Over time, your ears adapt to the volume level, so a volume level that does not cause discomfort might still damage your hearing.
To enjoy your PA Amplifier for a long time:
• Keep the PA Amplifier dry. If it gets wet, wipe it dry immediately.
• Use and store the PA Amplifier only in normal temperature environm en ts.
• Handle the PA Amplifier gently and carefully. Do not drop it.
• Keep the PA Amplifier away from dust and dirt.
• Wipe the PA Amplifier with a damp cloth occasionally to keep it looking new.
Modifying or tampering with the
’s internal components can cause a mal-
er function and might invalidate its warranty. If your
PA Amplifier should, take it to your local RadioShack store for assistance.
is not performing as it
PA Amplifi-
REPLACING THE FUSE
If the amplifier does not operate, you might need to replace the fuse on the back of the amplifier with another 7-amp, 250-volt fuse.
1. Unplug the amplifier from the AC outlet.
2. Turn the fuse holder cap on the back of the amplifier in the direction of the arrow, then pull out the cap to remove the fuse.
3. If the fuse is blown, replace it. Use only an identical fuse with the proper rating. The fuse must be 7 amps.
Insert the fuse into the fuse holder ’s socket, press the fuse holder back into the amplifier, then turn the fuse holder’s cap clockwise to tighten it.
Important:
see if it starts again before you assume a fuse needs to be replaced.
Caution:
than those specified. Doing so might damage your amplifier.
Let the amplifier cool down and
Do not use a fuse with ratings other
Care
9
ˆ
The FCC Wants You to Know
Your amplifier might cause TV or radio inter­ference even when it is operating properly. To determine whether your amplifier is caus­ing the interference, turn off your amplifier. If the interference goes away, your amplifier is causing it. Try to eliminate the interference by:
• moving your amplifier away from the receiver
• contacting your local RadioShack store for help
10
The FCC Wants You to Know
ˆ
Specifications
Input Impedance..........................................................................................................20 kOhms
Continuous Output Power
Stereo at 1 kHz .............................................................................. 125 Watts × 2 (8 ohms)
Stereo at 1 kHz .............................................................................. 175 Watts × 2 (4 ohms)
Bridged at 20 Hz to 20 kHz .................................................................. 250 Watts (8 ohms)
Bridged at 1 kHz .................................................................................. 350 Watts (8 ohms)
Total Harmonic Distortion ................................................................................ 0.1% at 80 Watts
Frequency Response (10 Hz – 50 kHz) ............................................................................ ±3 dB
Input Sensitivity .............................................................................................................. 0.775 V
Signal-to-Noise Ratio ................................................................................... 90 dB (A-weighted)
Speaker Impedance ................................. ... ... .................................... ... ......... A, B (4–16 ohms)
A+B (8–16 ohms)
Bridged (8–16 ohms)
Power Requirement ........................................................................................... 120V AC 60 Hz
5
Dimensions (HWD) ............................................................................... 5
Weight .......................................................................................................................... 27.53 lbs
Specifications are typical; individual units might vary. Specifications are subject to change and improvement without notice.
/6 × 19 × 141/4 Inches
(11.4 × 48.2 × 30.5 cm)
(12.5 kg)
Specifications
11
Limited One-Year Warranty
This product is warranted by RadioShack against manufacturing defects in material and workman­ship under normal use for one (1) year from the date of purchase from RadioSh ack comp any-owned stores and authorized RadioShack franchisees and dealers. EXCEPT AS PROVIDED HEREIN, Ra­dioShack MAKES NO EXPRESS WARRANTIES AND ANY IMPLIED WARRANTIES, INCLUDING THOSE OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE LIMITED IN DURATION TO THE DURATION OF THE WRITTEN LIMITED WARRANTIES CONTAINED HEREIN. EXCEPT AS PROVIDED HEREIN, RadioShack SHALL HAVE NO LIABILITY OR RE­SPONSIBILITY TO CUSTOMER OR ANY OTHER PERSON OR ENTITY WITH RESPECT TO ANY LIABILITY, LOSS OR DAMAGE CAUSED DIRECTLY OR INDIRECTLY BY USE OR PERFOR­MANCE OF THE PRODUCT OR ARISING OUT OF ANY BREACH OF THIS WARRANTY, IN­CLUDING, BUT NOT LIMITED TO, ANY DAMAGES RESUL TING FROM INCONVENIENCE, LOSS OF TIME, DATA, PROPERTY, REVENUE, OR PROFIT OR ANY INDIRECT, SPECIAL, INCIDEN­TAL, OR CONSEQUENTIAL DAMAGES, EVEN IF RadioShack HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Some states do not allow limitations on how long an implied warranty lasts or the exclusion or limita­tion of incidental or consequential damages, so the above limitations or exclusions may not apply to you. In the event of a product defect during the warranty period, take the product and the RadioShack sales receipt as proof of purchase date to any RadioShack store. RadioShack will, at its option, un­less otherwise provided by law: (a) correct the defect by product repair without charge for parts and labor; (b) replace the product with one of the same or similar design; or (c) refund the purchase price. All replaced parts and products, and products on which a refund is made, become the prop­erty of RadioShack. New or reconditioned parts and products may be used in the performance of warranty service. Repaired or replaced parts and products are warranted for the remainder of the original warranty period. You will be charged for repair or replacement of the product made after the expiration of the warranty period. This warranty does not cover: (a) damage or failure caused by or attributable to acts of God, abuse, accident, misuse, improper or abnormal usage, failure to follow instructions, improper installation or maintenance, alteration, lightning or other incidence of excess voltage or current; (b) any repairs other than those provided by a RadioShack Authorized Service Facility; (c) consumables such as fuses or batteries; (d) cosmetic damage; (e) transportation, shipping or insurance costs; or (f) costs of product removal, installation, set-up service adjustment or reinstallation. This warranty gives you specific legal rights, and you may also have other rights which vary from state to state.
RadioShack Customer Relations, 200 Taylor Street, 6th Floor, Fort Worth, TX 76102
We Service What We Sell
12/99
RadioShack A Division of Tandy Corporation Fort Worth, Texas 76102
32-2004
04A00
Printed in China
Loading...