The Compact disc (CD) is one of the most important development in recorded sound since advent of audio cassette. The German call them silver beer mats, which is not a bad description . CDs comes usually as plastic and aluminium and it is , indeed compact , measuring 12 cm across. It plays on one side only, and can play music lasting up to 75 minutes.
So the most obvious advantage of CD over IP (tape), is in saving storage space but that is only a small part of the story. The disc played or rather read by a laser. There is, therefore no physical contact and the disc retains its quality throughout repeated playing.
But the heart of the matter, in the words of early advertising slogan, is , no snap”, no crackle”, no pop.” Surface noise is all but eliminated, leaving the sound as clear as when it was first played in the concert hall or recording studio.
The technological difference between CD and conventional recording on IP or tape, is summed up in the words digital and analogue. The traditional analogue system stores an analogy of the music in the grooves of the IP record or the magnetic fields of the tape. With the digital system used by the CD, the information is quantified in the number or set of numbers . digital recordings can cover a range of sound corresponding to 90 decibel, but are prone to noise and distortion. They are also subject to ageing, wear and dirt , given reasonable handling, the CD should suffer none of these things.
Apart from its outstanding and dynamic range, the advantage of the digital system is to bring in microprocessors, which allow you to select the tracks you want, play them in the order you want, and, if required, to play the same track, or part of track, a predetermined number of time.
Finally, the CD system is absurdly easy to work. Enclosed players , more like cassette decks than record players, generate none of the fear of turntables with their delicate pick-up arms.
