Other components

Chapter Other components

Teach Yourself Electricity and Electronics Third Edition Book
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Teach Yourself Electricity and Electronics Third Edition Book

  • be received clearly. Commercially manufactured tuners often have CD and tape players built in.The amplifierIn hi-fi, an amplifier is usually a self-contained box that delivers medium or high au-dio power to a set of speakers. There is at least one input, but more often there areseveral: one for a CD player, another for a tape deck, another for a radio tuner, andanother for a microphone or turntable.Hi-fi amplifiers are available from retail and mail-order houses. Input requirementsare a few milliwatts; the output can range up to hundreds of watts. Prices increase withincreasing power output. Some amplifiers contain built-in tuners, CD players, or tapedecks. A simplified hi-fi amplifier forms the basis for a public-address system. Massiveamplifiers are used by popular music bands. Some such systems employ vacuum tubes,because tubes offer electrical ruggedness and linearity.Speakers and headsetsNo amplifier can deliver sound that is better than the speakers will allow. Speakersare rated according to the audio power they can handle. It’s a good idea to purchasespeakers that can tolerate at least twice the audio output power that the amplifiercan deliver. This will ensure that speaker distortion will not occur during loud, low-frequency sound bursts. It will also prevent physical damage to the speakers thatmight otherwise result from accidentally overdriving them.Good speakers contain two or three individual units within a single cabinet. Thewoofer reproduces bass (low-frequency) sound. The midrange speaker handlesmedium and, sometimes, treble (high) audio frequencies. A tweeter is designed espe-cially for enhanced treble reproduction.Speakers are sometimes called loudspeakers. This term does not have anything todo with the relative volume or power-handling capability of the components. It proba-bly arose in the early days of radio, when earphones or headsets were the norm. Com-pared to the output from a typical headset, of course, speakers really are loud.For privacy of listening, and to avoid irritating other people when you really wantto “blast” yourself with some good music, a good pair of headsets is important. Headsetscome in at least as many different forms as speakers. In general, they are rated accord-ing to how well they reproduce sound. But this is a subjective consideration. Equally ex-pensive headsets can, and often do, exhibit huge differences in the quality of the soundthat they put out. Not only that, but people often disagree about what, exactly, consti-tutes “good sound.”If you’re buying speakers or headsets, it’s a good idea to listen to them in action be-fore you part with your money. With speakers, try to test them under conditions similarto those in the place where they will be used. Speakers never sound quite the same in astore as they do in a bedroom or living room.Other ComponentsMost hi-fi systems are more than “just the basics.” Features such as balance control,tone control, and graphic equalizers are common. Audio mixers are sometimesOther components591