Instruction/ maintenance manual of the product MPA-50 Radio Shack
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Owner’s Manual Please read before using this equ ipment. MPA-50 40-Watt PA Amplifier 32-2002.fm Page 1 Friday, February 11, 2000 11:36 AM.
2 ˆ Contents Features ......... ................ ................ ................ ................. ................ ................ ......... 3 Preparation ....... ................ ................ ............. ................. ................ .
3 Features ˆ Features Your RadioShack MPA-50 40- Watt PA Amplifier gives you 40 watts of solid power for your public address (PA) sys- tem. The built-in three-ba nd equalizer enables you to tailor the sound to fit your environment. Its wide frequ ency re- sponse easily handles amplification of voice and music.
4 Preparation ˆ Preparation PRESETTING THE CONTROLS Warning: A sudde n high out put from the amplifier could dama ge your hearing or the speakers conn ected to the amplif i- er’s output.
5 Making Connections ˆ Making Connections Important: Connect all auxiliary equipment and speakers before connecting pow er. PHONO L (Left) a nd R (Right) Input Jacks — Connect a turntable with a magnetic cart ridge. To avoid di stortion, do not connect a high-le vel audio input source to these jacks.
6 Speakers ˆ Speakers SPEAKER PHASING Phasing is the direction the sp eaker cone moves with re feren ce to the polari- ty of the con nection wires. Prope r phas- ing is import ant when you use mo re than one speaker in the same room or area.
7 Speakers determine if your speakers ar e connect- ed in series, pa rallel, or series /parallel combined. Note: We recommend that you use speakers th at are rated the same (f or example, all 8- ohm speakers ) for all se- ries or parallel connections.
8 Speakers One Speaker Connect the speaker ’s negative (– ) ter- minal to the amplifier’s COM (common) terminal. Th en connect the sp eaker’s positive (+) terminal to the amplifier’s terminal that matche s the speaker’s im- pedance.
9 Speakers Speakers in Parall el 1. T o determine the total impedance of speakers connected in parallel, divide the impe dance of one speaker by the numbe r of speakers .
10 Speakers 4. T o determine the total impedance of speakers connected in serial and parallel combined, divide the imped- ance of one pair of speakers by the number of pairs.
11 Speakers Cautions: • Before you connect th e speakers, be sure the total wat tage of the primary taps you intend to use do es not exceed the am plifier’s maximum 40-watt output power rating. • Avoid multiple connections to the amplifier ’s 70V an d COM terminals.
12 Controls and Operation ˆ Controls and Operation MICROPHONE 1 and 2 Inputs — Con- nect any standard d ynamic microphone with a 1 / 4 -inch plug. POWER Switch and Indicator — Press the bottom h alf of the switch to turn on the amplifier. The indicator lights.
13 Troubleshooting ˆ T roubleshooting If you should ru n into difficulties, che ck the wiring of the system. Are the re any short circuits in th e speaker wirin g? Have you provided adequate ventila - tion? Did you calculate sp eaker imped- ance corr ectly? Be sure microphon es and connecting cables are not defective.
14 Care ˆ Care To enjoy your MPA-50 40-Watt PA Am- plifier for a long time: • Keep the amplif ier dry . If it get s wet, wipe it dry immediately . • Use and store the amplifier only in normal temperature environments. • Han dle the amplifier gently and carefully .
15 Specifications ˆ Specifications Output Power at 1 kHz, 10% THD ................. .............. ................ .............. .............. .... 40 W atts Power Bandwidth at 1W , 10% THD, Auxiliary Input ........................................
32-2002 81 108 1780C 02A00 Printed in China RadioShack A Division of Ta ndy Corporation Fort Worth, Texas 76102 Limited One-Y ear Warranty This product is warranted by RadioShack against manufactu rin.
An important point after buying a device Radio Shack MPA-50 (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought Radio Shack MPA-50 yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data Radio Shack MPA-50 - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, Radio Shack MPA-50 you will learn all the available features of the product, as well as information on its operation. The information that you get Radio Shack MPA-50 will certainly help you make a decision on the purchase.
If you already are a holder of Radio Shack MPA-50, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime Radio Shack MPA-50.
However, one of the most important roles played by the user manual is to help in solving problems with Radio Shack MPA-50. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device Radio Shack MPA-50 along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center