Audio Engineering

Other Digital Audio Devices 631

You can also buy DAM CDs over the Internet. They often feature unknown artists and are
priced accordingly, although you should not expect a large selection of classical music to be
available. The CD is usually offered on the Web page for the artist, and costs are kept low by
using CD-R so that the music you want is transcribed to a CD when you place your order.

● Some older CD decks cannot cope with DAM CDs that inevitably use

multisession methods.

21.9 DVD and Audio ....................................................................................................

The CD format was standardized at a time when digital recording of sound on disc was
still an uncharted realm, full of possibilities and surprises, and CD technology strained
at the limits of what was possible, particularly A-D and D-A conversion methods. The
use of lasers to write the master discs, although not new because of the Philips “ silver
discs ” used for video recordings, was unfamiliar to many recording companies, and the
extent of the packing of bits on the CD stretched the pressing capabilities of all but a few
users. Now, at least two decades on, we can see that the potential of the little CD is much
greater than we could have hoped for.

DVD, originally the acronym of digital video disc, is now taken to mean digital versatile
disc and refers to a more recent development of CD technology. This was originally
directed to recording full-length fi lms on CD, hence the “ video ” in the original title, but
the idea has been extended to a universal type of disc that can be used for fi lms, audio, or
computer data interchangeably. The main difference, at present, is that there are very few
DVD writing drives available, and these few are expensive by computing (although not
by hi-fi ) standards.

● An important feature of a modern DVD computer or TV drive unit is that it will

accept conventional CDs as well as DVD discs.

The DVD holds much more data, can transfer it faster, but is as easy to reproduce by
stamping processes as the older CDs (which, alas, does not mean that it will be sold at
reasonable prices in the United Kingdom, even if a DVD costs so much less to produce
than a videotape). Eventually, DVD will be the one uniform recording format, replacing
cassettes, DAT, videotape, and CD-ROM. A DVD drive is already virtually a standard
item on computers, and the manufacturers claim that in a time of 3 years it has become
the most successful electronics product of all time for home use ( Figure 21.4 ).