Radio Shack 32-2001 Скачать руководство пользователя страница 6

6

3. Touch the positive end of a 1.5-volt

flashlight battery to the speaker ter-
minal that does not have the wire
attached to it.

4. Touch the negative end of the bat-

tery with the lose end of the wire
attached to the other speaker termi-
nal. Note the direction of the cone
movement — inward or outward.

5. If the speaker cone moves outward,

the speaker terminal where you
touched the positive end of the bat-
tery is positive. Mark that terminal
with a + and mark the other terminal
with a –.

If the speaker cone moves inward,
the speaker terminal with the wire
attached that touched the negative
end of the battery is positive. Mark
that terminal with a + and mark the
other terminal with a –.

6. Remove the wire.

Repeat Steps 2–6 for each speaker with
unmarked terminals you plan to connect
to the amplifier.

DETERMINING TOTAL 
SPEAKER IMPEDANCE

Caution: A total speaker impedance
that is higher than 16 ohms (

Ω) 

or lower

than 4 ohms can damage your amplifier
or speakers. Be sure to make the proper
connections.

Before you connect speakers to the am-
plifier, you must determine the total
speaker impedance. In determining the
total speaker impedance, you must first
determine if your speakers are connect-

ed in series, parallel, or series/parallel
combined.

Note: We recommend that you use
speakers that are rated the same (for
example, all 8-ohm speakers) for all se-
ries or parallel connections.

• Speakers are connected in series

when the first speaker’s positive ter-
minal is connected to the next
speaker’s negative terminal. Deter-
mine the total impedance of speak-
ers connected in series by adding
up the individual impedances of all
the connected speakers.

For example, if you want to connect
two 8-ohm speakers in series, add 8
(the impedance of one speaker)
plus 8 (the impedance of the other
speaker) for a total speaker imped-
ance of 16 ohms.

• Speakers are connected in parallel

when all their negative terminals are
connected together and all their
positive terminals are connected
together. For speakers rated the
same, find the total impedance of
speakers connected in parallel by
dividing the impedance of one
speaker by the number of speakers.

For example, if you want to connect
two 8-ohm speakers in parallel,
divide 8 (the impedance of one
speaker) by 2 (the number of speak-
ers) for a total speaker impedance
of 4 ohms.

32-2001.fm  Page 6  Friday, February 4, 2000  7:53 AM

Содержание 32-2001

Страница 1: ...Owner s Manual Please read before using this equipment MPA 40 20 Watt PA Amplifier 32 2001 fm Page 1 Friday February 4 2000 7 53 AM ...

Страница 2: ...eaker 7 Two or More Speakers Without Transformers 7 Multiple Speakers with Transformers 9 Controls and Operation 11 Troubleshooting 12 Care and Maintenance 13 Replacing Fuses 13 DC Cable 13 Amplifier 13 Specifications 14 Notes 15 2000 Tandy Corporation All Rights Reserved RadioShack and RadioShack com are registered trademarks used by Tandy Corporation 32 2001 fm Page 2 Friday February 4 2000 7 53...

Страница 3: ...e Control lets you customize the sound to suit your personal preferences depending on the acoustics speakers and sound source Five Speaker Terminals make speaker connection easy Your amplifier is ETL listed to UL stan dards and meets all applicable FCC standards 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 O...

Страница 4: ...t source such as a heat vent or radiator which can cause the amplifier to overheat ˆ Making Connections AUX CD Input Jack connect any high level sound source such as a tape deck CD player or receiver To con nect a stereo audio source to this jack use a shielded Y adapter not supplied available at your local RadioShack store PHONO Input Jack connect a turnta ble with a moving magnetic cartridge To ...

Страница 5: ...efore you plug in the AC power cord ˆ Speakers SPEAKER PHASING Phasing is the direction the speaker cone moves with reference to the polari ty of the connection wires Proper phas ing is important when you use more than one speaker in the same room or area Out of phase speakers can lose up to one half of their potential volume and can have a significantly decreased bass effect Speakers are in phase...

Страница 6: ...ker impedance In determining the total speaker impedance you must first determine if your speakers are connect ed in series parallel or series parallel combined Note We recommend that you use speakers that are rated the same for example all 8 ohm speakers for all se ries or parallel connections Speakers are connected in series when the first speaker s positive ter minal is connected to the next sp...

Страница 7: ...te push terminal tab and inserting the end of the twisted wire into the terminal s hole Then release the tab to secure the wire You can connect one or more 4 8 or 16 ohm speakers with or without trans formers between the amplifier s output and the speakers input To ensure equal volume from each speaker all the connected speakers should have the same impedance rating One Speaker Connect the speaker...

Страница 8: ... in this example Speakers in Parallel 1 To determine the total impedance of speakers connected in parallel divide the impedance of one speaker by the number of speakers For example if you want to connect two 8 ohm speakers in parallel divide 8 the impedance of one speaker by 2 the number of speak ers for a total speaker impedance of 4 ohms 2 Connect the speakers negative terminals together 3 Conne...

Страница 9: ...e number of speaker pairs for a total speaker impedance of 8 ohms 5 Connect the negative terminals of all pairs of speakers to the ampli fier s COM terminal 6 Connect the positive terminals of all pairs of speakers to the ampli fier s terminal that matches the total speaker impedance 8Ω in this example Multiple Speakers with Transformers For complex multiple speaker arrange ments that require many...

Страница 10: ...ting Avoid multiple connections to the amplifier s 70V and COM terminals Follow these steps to make the connec tions 1 Connect a wire from the amplifier s 70V terminal to the transformer s pri mary tap that matches your speaker s wattage rating Note Usually the wattage connec tions on the primary side of the transformer are the same for all speakers If you want a particular speaker to have a highe...

Страница 11: ...nd set to play if needed set this control to its mid range setting 5 Adjust this con trol again after adjusting the source mix ing controls Caution Be careful not to raise the vol ume level too high Doing so might over load the system MIC 1 and MIC 2 Source Mixing Con trols adjust the input level for each of the two microphones to get the proper volume and balance PHONO AUX Source Mixing Control a...

Страница 12: ...ave feedback problems reposi tion your microphones and speakers or adjust TONE or MASTER VOLUME to a lower setting If the amplifier does not work at all check the fuse on the rear panel If it is blown replace it with one of the same size and type see Replacing Fuses on Page 13 If you are operating the unit from a 12 volt DC power source check the fuse in the supplied cable that connects to your ve...

Страница 13: ...ess POWER check the fuse and if necessary re place it with one of the same size and type To replace the fuse unscrew the tip of the cigarette lighter plug Then remove the old fuse and insert the new fuse Se cure the fuse by reattaching the plug s tip Amplifier The power fuse protects your amplifier from power voltage or current surges when operating it from an AC power source If the POWER indicato...

Страница 14: ...uency Response at 8 ohms 1W MIC1 130 Hz 20 kHz MIC2 130 Hz 20 kHz AUX CD 130 Hz 20 kHz PHONO 100 Hz 12 dB 10 kHz 13 dB Hum and Noise at 8 ohms at Master Volume Minimum 1 mV at Master Volume Maximum 10 mV Tone Control High Cut at 10 kHz 15 dB Power Requirement 120V AC 60 Hz Dimensions HWD 315 16 123 4 105 8 Inches 99 5 324 270 mm Weight 9 lb 4 08 kg Specifications are typical individual units might...

Страница 15: ...15 ˆ Notes 32 2001 fm Page 15 Friday February 4 2000 7 53 AM ...

Страница 16: ... 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 un less 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...

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