This is intended as a broad introduction to the world of true hi-fi. It does not refer to those little 'hi-fi systems' where you get everything in one or two little boxes with two speakers attached. If you have one of those and are happy with it, read no further; this will only upset you.

True hi-fi is the equipment required to bring to your ears, in your home, as faithful a reproduction of the original music as is possible (or affordable). Quite a different experience. The delights of 'surround sound', 'multi-channel sound', 'home cinema' and 'multi-room systems' are ignored, here our concern is stereo or, more fashionably in the USA, 'two channel' sound.

Let's look at the components.

Sources

At the time of writing, the sources available are LP (yes, those funny big black discs with grooves in them that crackle and hiss), CD, and FM radio broadcasts. Coming soon are SACD (Super Audio CD) and DVD-A (Using DVD discs for audio reproduction). Cassettes are OK. Reel-to-reel tape is good, but for the purposes of this entry, extinct. Minidisc and MPEG formats are generally not of sufficient quality yet; they do not produce sufficient encoded information for an accurate reproduction of the original music.

Turntables

Yes, really. If you hear a clean LP played on a very good turntable, you will be amazed. No hiss, crackle and pop. And the sound is rich and full of detail. A turntable, or rather the needle attached to the cartridge, which is attached to the arm, which is attached to the turntable, produces analogue signals (sine wave). There are many who contend that they can hear a real difference between the same music played on an LP and then on a CD - with the LP sounding better. All the components can be bought separately (motor, turntable, arm, cartridge) and the total can cost well over US$10,000 should you be so inclined. You can also buy decent complete systems from $300. There is a lot of sophisticated engineering in getting a turntable to revolve exactly at 33rpm consistently, and holding the needle with just the right pressure at just the right angle to extract the maximum information from the groove. Here is hi-fi at its most intricate. The trouble (or joy) of turntables is that they require constant interruption to put LPs on, take them off, find the right track and so on. The advantage is that the source material (ie secondhand LP's) is very cheap, once you have a good cleaning system.

CD Players

These are the workhorses of recorded music these days. There are varying price levels and degrees of sophistication. Information is stored on a CD in digital form, ie little bursts of information, and you may think that there can be little difference between one player and another in extracting these discreet packets of information. Wrong. You need a good solid tray that's not going to wobble, an accurate laser and electronics that sample the 'bits' as often as possible. Today the standard rests at 24-bit oversampling, and is looking at 96-bit for the future. Early reports of the SACD system are very good and manufacturers are beginning to produce the necessary players. The DVD-A system is not looking quite so likely to be favoured. Some CD players can hold three or more discs on a tray, and others have stacking systems for up to 300 discs. Generally, as far as hi-fi is concerned, the simpler, the better.

DVD Players

Closely related to a CD player, these extract video signals as well as audio players. What's more, there are usually five or seven channels of audio (surround sound) instead of the conventional two (stereo). It is usual for DVD players to be able to play ordinary two channel CDs as well as DVD discs. The quality is not the same as a dedicated CD player, but if you don't want to buy both, test the CD replay before you buy.

Tape Decks

If you wish, for example, to record tracks from CDs to play on a tape in your car/walkman, you need a cassette tape deck of a quality equal to your other components. These are becoming harder to find as minidiscs and MPEG files are increasingly in vogue, and new cars come with CD players fitted. CD recorders are on the market, but yet to descend to reasonable prices.

DAC

The Digital to Analogue Converter takes a digital signal (eg from a CD player) and turns it into an analogue signal. This smooths out the discreet bits of digital information into a warmer and more detailed (to the ear) sound. It is beginning to fall into disuse as CD Players become better, or incorporate such a device within them. You might ask 'DACs, why?'. A valid question as the CD players that would benefit most, ie cheap ones, don't often have the digital or optical output to connect to a DAC, whereas those that do have the connections are likely to be of reasonable quality anyway.

FM Tuner

As the name suggests, the tuner collects the signal from a radio station (via an aerial) and turns it into an electrical signal. FM broadcasts are generally of good quality, and many stations now offer digital broadcasts. You may like to put off a purchase for a year or two until tuners for DAB (Digital Audio Broadcast) are widely available. Note also that TV satellite and cable services also broadcast many FM radio stations, and you can use your decoder as a source. In America, tuners are often combined with an integrated amplifier, and the two together are called a receiver.

Pre-Amplifiers

This is the bit with all the knobs for volume, source, and maybe tone on the front of your system and all the wires in the back. In American equipment it is sometimes called the control centre. Often, especially at the budget end of the market, the pre-amp is combined with the power amp(s) (qv) in an integrated amplifier. In addition to connections for your CD player, tuner and tape deck, you will also have inputs available for use with your TV, VCR and PC so that you can listen to these through your sound system, should you so desire. There may also be a socket for headphones to be plugged into.

Power Amplifier

This is the engine. The power amp turns the tiny signal from the source equipment into a much more powerful signal to power the loudspeakers. Note that the output from a turntable is even smaller than from a digital source, and requires a separate boost amplifier to bring it up to line level. Beware, if you want to use a turntable, not all amplifiers have this phono stage, and have line inputs only. Needless to say, the phono stage is available separately, at extra cost. In more sophisticated systems you can have a power amplifier for each channel, left and right, or even for each separate speaker within each loudspeaker. The power amp has no knobs; it is controlled by the pre-amplifier.

Some amplifiers incorporate the old-fashioned valves that pre-dated transistors. These are thought by some to produce a warmer tone. This was certainly true when CD players were introduced, but the very detailed signal from the best CDs and CD players has improved things immensely in recent years. Diehards and purists remain unconvinced, however.

Loudspeakers

It is the tone of the speakers that, provided all else is good, will make the sound of your system. They are also the largest piece of furniture in the system, so you will probably be paying some attention to the design.

The most basic speakers contain a tweeter which is a small speaker for the highest sounds, a mid-range speaker which covers the widest range of sounds that the human ear can hear, and a bass speaker which covers the lowest ranges. Some speakers combine tweeter and mid-range in a single concentric design. Because high frequency sound travels a little faster and is more focused than bass frequencies, sometimes the tweeter is mounted a few centimeters back from the plane of the bass speakers. Most speakers require some space around them, to move the air, so if your only option in a small room is to place them on bookshelves, be sure to get specially designed bookshelf speakers.

A recent development is the separate sub-woofer which deals with low bass sounds and is particularly useful in home cinema applications. If using this with a budget stereo system, it means you can have separate, much smaller speakers for the mid-range/high frequencies and put the sub-woofer under a table out of the way. Because the higher range speakers do not need so much air around them, they can be accommodated on shelves or wall brackets for example.

Most speakers are passive, they take their power from the amplifier. Some, however, are active, they incorporate the amplifier within the cabinet. This eliminates the need for a power amplifier in the system, but have you got the requisite power points?

There is a type of large, flat loudspeaker that works on a different principle. These electrostatic speakers occupy a huge space, but the sound nears perfection. If you ever noticed the big black grilles in the corner of the Friends set, that's what they are.

There are also other types of flat speakers designed to be unobtrusive and based on a different (NXT) technology. Only your ears can decide the compromise between appearance and sound.

There is a fashion developing for making speakers that cover a wider range of sound than the human ear can hear (as imprinted on SACD's), the reasoning being that sound you cannot hear does affect the way you hear the sounds that you do hear. Having listened, there does seem to be something in the theory.

Headphones

There are very high quality headphones available. These make listening possible without disturbing other members of the household. There is no doubt that listening through good headphones in the dark enables you the get the very finest detail from a performance. Whether or not the music connects as directly to the emotions as when heard through loudspeakers is another matter. As you would expect, dedicated amplifiers are available for headphones.

Interconnects

These are the cables that join the various electronic bits together. The better the cable, the more signal gets through to the amplifiers, enabling them to make more of the music.

Speaker Cables

A different sort of cable that takes the sound from the amplifiers to the speakers. This can be several metres long and it is important that no interference from other electrical apparatus in the house affects the sound signal.

Stands

In order for them to function properly, it is important that all the equipment, and especially the turntable, CD player and speakers are held firmly on rigid platforms. Stands are made especially for the purpose, often with spikes on the legs to anchor them firmly to the floor, even through carpets.

The Room

Finally, do not forget that the shape and size of your room, and the materials within it, will affect the sound. Some thought, therefore, must go into how you place your speakers within the room. Many speakers need to have some space around them to produce the best sound.

So, having absorbed all the above information, two questions remain, Why? How?

If you are used to a small mini hi-fi system, the first time that you hear a true hi-fi set up, you will be amazed. Truly. The bass will hit your stomach, the strings make you weep and the singer will be there with you. You will hear the music as it was played (or recorded). Even at the budget end of true hi-fi, for the same money as the better mini-systems, the experience is quite different.

But, and it is a big but, only you can decide how much that true hi-fi experience is worth to you. Very few can afford the tens of thousands of dollars or pounds that the very best can cost, so you have to be ready to compromise. Once you have made the initial quantum jump from the mass-produced systems to the basic hi-fi set-up, you will never be satisfied, you can always improve it incrementally, but you will never, after the first few honeymoon months, think you have the perfect system. It is an expensive hobby. You have been warned...

So, how to get started? The first step might be to take your favourite CD to a good retailer that has a listening room, and ask to hear it played on some different systems. In the UK, these might include better department stores (John Lewis are surprisingly good), specialist shops such as Richer Sounds or Sevenoaks Hi-Fi, or a hi-fi dealer, of which there is usually at least one in most major cities. There are many listed in the hi-fi magazines. It's recommended that you avoid the specialist magazines' advice columns and reviews until you have begun to form your own opinions of what you want, but when you are ready there are many to help you. Stereophile in the USA, Hi-Fi News and What Hi-Fi in the UK are perhaps the best known, but there are several others on the newsagents racks.

Some Guidance

Before you even start, decide your budget, and make a firm resolution to stick to it. It is possible, just, to start with $1000 or £700 and put together a simple system (CD, amp, speakers, stands and cables) that will 'blow away' any micro/midi system you could buy for the same money. If you can manage twice that, there is an appreciable difference. Double it again and you are beginning to look at serious kit. There is also a very viable alternative, to buy second-hand. Good hi-fi equipment doesn't die, it just goes out of fashion.