Technical information

Cantilever The thin rod within a turntable's cartridge that transmits the movement
of the stylus in response to a record's groove to the interior components of the
cartridge that generate the electrical signal.
Carrier A sine wave which may be modulated by a signal to form an AM signal.
The frequency of the carrier must be significantly higher than that of the
modulating signal. In practice, the carrier is usually a radio frequency sine wave,
and so is two orders of magnitude higher in frequency than the signal.
Cartridge The device that converts the movements of a stylus in the grooves of an
LP record to electrical signals. The cartridge is a small, light-weight device,
secured to the end of a turntable's tonearm by means of two screws mounted
12.5mm apart. The movements of the stylus are transmitted through a
cantilever to some form of electrical generating device. The two main types of
cartridge are ceramic and magnetic. The latter is further subdivided into moving
magnet and moving coil types.
CAV Constant Angular Velocity – as opposed to CLV. A method of spinning a disc
or disk carrying a signal. CAV means that the rate of spin remains unchanged
regardless of where the reading device is on the surface. An LP record is an
example (which is part of the reason why the outer tracks tend to sound better
than the inner ones). While CDs are designed to be operated at a CLV, fast CD-
ROM drives actually run them with a CAV.
CBR Constant bit rate – as opposed to variable bit rate. The signal (video or
audio) is digitally encoded so that a fixed amount of data flows each second. This
has the advantage of making the space requirements for the signal easy to
calculate. DTS and Dolby Digital are both CBR systems, as are the earlier
versions of MPEG audio and video compression. Most MP3 files are CBR
encoded, although the format does support VBR as well.
CD Compact Disc -- 120mm diameter optical disc. It carries a digital PCM
representation of a two channel analogue signal, along with error correction
information. The analogue signal is sampled at 44,100 hertz and uses a bit
depth of 16.
CD emphasis When the compact disc was first developed, the designers
implemented a rather surprising element in its specification. This was a pre-
emphasis, de-emphasis cycle. In brief, this permits the treble in the source signal
to be boosted before the CD is mastered (pre-emphasis), recording this fact by a
special bit in the package around each segment of audio data, and cut again by
the CD player (de-emphasis). When cut, it also had the advantage of reducing any
noise due to the recording medium.