Spdif Explained; Connecting Spdif; Patching In Speaker Processors - ALLEN & HEATH PA-CP Series User Manual

SPDIF explained SPDIF stands for "Sony
Philips Digital InterFace".
developed by the consumer electronics industry
for interfacing digital audio signals. It has the
advantages that audio can be passed from one
digital device to another without the need for
analogue conversion, and that both the left and
right signals are carried on a single cable. It has
become popular with
consumer and professional audio and computer
products. There are two types for SPDIF
connection, coax and optical.
RCA connector and 75 ohm coaxial cable.
Toslink is the optical version that uses fibre-optic
cable. The coax version can work with cable
lengths up to 15 metres.
30
It is a standard
manufacturers of
Coax uses the
2TRK INPUT
A pair of RCA phono sockets accepts the
input from a stereo playback devices such as a CD, MiniDisc,
DAT or tape player. Use it to monitor a stereo recording in the
console headphones, or to route a stereo source to the LR mix
for background music. The input is unbalanced and has 0dBu
line level sensitivity.
2TRK OUT
The LR mix is also available at a pair of RCA
phono sockets for connection to a 2-track recording device
such as MiniDisc, DAT or tape recorder.
unbalanced and operates at 0dBu line level. It can be sourced
pre or post the LR faders and is buffered from the LR
connections to ensure that plugging in here does not affect the
main output.
2TRK DIGITAL OUT
output described above is available from this RCA phono
socket. It is in SPDIF format and uses high grade ADC
converters. Plug into the SPDIF coax input on equipment such
as recorders, digital audio processors and computer sound
cards. Bypassing the input ADC devices on such equipment
can reduce audio quality degradation, especially if they use low
grade devices.
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Connecting SPDIF Use 75 ohm coaxial cable. Pre-
made SPDIF cables are readily available. You can also use
standard 75 ohm coaxial video cable. Do not use standard
RCA to RCA audio cables.
Do not plug SPDIF
connections. While it is unlikely to cause physical damage
it can result in unpleasant audible noise.
AB SLAVE OUT
TRS line outputs for connecting to
external line level equipment such as booster amplifiers and
speaker processors. They are impedance balanced and can
work with balanced or unbalanced inputs. Operating level is
0dBu. The output follows the panel AB source selection and
EQ settings. It does not break the signal path to the AB
amplifiers.
AB AMP INPUT
TRS inputs to plug external equipment
directly into the console A and B amplifiers.
unbalanced and operate at 0dBu line level. Plugging into these
sockets automatically breaks the internal signal path so that the
amplifiers are fed by the external signals only. This lets you
use the amplifiers for other purposes, or for patching in
equipment such as speaker processors.
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Patching in speaker processors Several loudspeaker
manufacturers provide processor units to equalise the
response of their speakers.
characteristics of the driver or box design. Typically, the unit is
positioned just before the amplifier in the signal path. First
read the instructions provided with the speakers. Plug the AB
SLAVE OUT into the speaker processor. Plug its outputs back
into the AB AMP IN sockets.
To avoid loud thumps or unexpected noises turn
down the console A and B amplifier level controls while
patching into the AMP IN sockets.
The output is
A digital version of the 2-track
signals into analogue
They are
This is to compensate for the
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