Technical information

the main speakers; so home theatre receivers incorporate a system to allow the
sound to these speakers to be (adjustably) delayed by some milliseconds.
Title The major divisions for content on a DVD Video disc. Typically the movie is in
a single Title, while the trailer is in another Title and so forth. This is the
equivalent of a Group on a DVD Audio. A Title is normally subdivided into
Chapters.
Tone controls Labelled 'bass' and 'treble', fitted to a preamplifier these provided a
means of boosting or cutting the bass or treble of the signal. They typically
provide up to ten decibels of boost or cut at 50 hertz for bass and 10,000 hertz
for treble. Best avoided for high fidelity.
Tonearm Position the attached cartridge in the correct alignment to play an LP
record. Is normally pivoted at the back and provides for an adjustable tracking
weight by the use of a spring-loaded or weight-loaded mechanism; and usually have
a damped cueing lever to allow the stylus to be gently lowered to the surface of
the record. Over the years some makers have provided parallel movement
tonearms which do not use a pivot. In theory these should track the LP better,
but are difficult to design to work well.
Toroidal transformer See transformer.
TOSLink DVD players can be connected to digital audio decoders by means of a
digital signal cable. One kind uses wires and sends an electrical signal. TOSLink
cables use optical fibre and send an optical (or light) signal. More correctly,
TOSLink refers to the kind of plug on the end of such cables. This is roughly
square shaped with a small ridge to allow it to click into, and be firmly held by, a
socket. Some portable Minidisc recorders and CD players can receive or
generate an optical digital signal but these generally require a cable with a
different plug, shaped somewhat like a standard 3.5mm stereo headphone plug.
Total harmonic distortion All the harmonic distortion components added together
to give a summary measure, though often misleading. The imperfection resides in
the fact that, audibly, some of the harmonic components are worse than others.
In particular, odd-ordered harmonics from the fifth and up are particularly audible
in audio systems, whilst even harmonics (produced by valves) are practically
inaudible. Solid state amplifiers typically offer THD ratings of less than 0.1% at
rated power output but can still have audible harmonic distortion characteristics
(often heard as a sheen or ‘metallic’ overlay to the sound. Valve amplifiers might
offer a 2% THD but sound extraordinarily clean and musical.