Avalon VT-747SP - Appendix A - Glossary

Appendix A - Glossary
amplification – The process by which a
signal level is increased.
amplitude – The distance above or below the
centerline of a signal’s waveform. The greater
the distance from the centerline, the larger
the pressure variation or electrical signal.
attack – The initial transient or first part of the
envelope of a signal. The beginning of a note.
attenuate – To reduce the signal level
balanced – In a classic balanced audio
circuit, the two legs of the circuit (+ and -) are
isolated from the circuit ground by exactly the
same impedance. Additionally, each leg
carries the signal at exactly the same level
but with opposite polarity. Balanced input
circuits can offer excellent rejection of noise
and grounding loops.
balanced line – A cable having two
conductors and a ground connection and
often surrounded by a shield. With respect to
ground, the conductors are at equal potential
but opposite polarity. These lines are often
used in professional setting to reduce or
eliminate induced noise and interference from
external electromagnetic sources.
bandwidth – The band of frequencies that
pass through a device with a loss of less than
3dB, expressed in hertz or in musical
octaves.
channel – A single functional path in an audio
circuit.
clipping – A cause of audio distortion that is
the result of excessive gain requiring the
peaks of the audio signal to rise above the
capabilities of the circuit.
compressor – In effect, an automatic fader.
When the input signal exceeds a
predetermined level, called the threshold, the
gain is reduced by the compressor and the
signal is attenuated.
compression ratio – The ratio of signal
dynamic range between the compressor input
and the output above the device’s set
threshold point (such as 2:1, 4:1, 20:1).
console – A term for a sound mixer, usually a
large desk-type mixing board used to mix
together multiple track musical material.
crosstalk – The unwanted leakage of a
signal from one channel or track onto another.
decibel (dB) – A unit of audio measurement
of sound pressure level (SPL), signal level,
and changes of difference in signal level. The
decibel is a logarithmic (log) mathematical
function that reduces large numeric values
into smaller, more manageable numbers.
Decibel is calculated as 10 times the log of
the ratio of two powers, and 20 times the log
of the ratio of two voltages.
dBm: Decibels referenced to 1 milliwatt.
dBu or dBv: Decibels referenced to 0.775
volt.
dBV: Decibels referenced to 1 volt.
Page 37
Avalon Vt-747sp Operation Manual
Glossary
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