Allenheath PA28 User Manual download pdf (Page 30)

30 PA User Guide

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. The output is

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 A digital version of the 2-track

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.

☺ 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 signals into analogue

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. 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 is not

affected by the AB level controls. It does not break the signal

path to the AB XLR outputs.

AB MAIN OUT Rear panel XLR line outputs for

connecting to external line level equipment such as speaker

processors and amplifiers. They are electronically balanced

and operate at 0dBu. They are affected by the A and B level

controls. Use good quality 2-core shielded signal cable for

best results.

 Electronically balanced outputs use a 3 wire

connection to provide improved signal drive and interference

rejection when plugged into balanced equipment inputs.

Signal hot (+) = pin 2, signal cold (-) = pin 3, ground (cable

shield) = pin 1. The output generates equal level but opposite

polarity signals on pins 2 and 3. The pin 3 (-) signal gets

inverted by the receiving equipment input and therefore adds

to the pin 2 (+) signal. Interference, on the other hand, gets

picked up equally and with the same polarity on both the pin 2

and pin 3 wires. Because of the input stage inversion it

therefore cancels and is rejected leaving a clean audio signal.

The balanced outputs can work with unbalanced equipment

inputs by linking the XLR pin 3 (-) to pin 1 (ground).

 SPDIF explained SPDIF stands for “Sony

Philips Digital InterFace”. It is a standard

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 manufacturers of

consumer and professional audio and computer

products. There are two types for SPDIF

connection, coax and optical. Coax uses the

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.

BALANCED PIN2 = +

MAIN OUTPUT

1 2 ... 25 26 27 28 29 30 31 32 33 34 35 36

Comments to this Manuals

No comments

Allenheath PA28 User Manual Page 30

Comments to this Manuals

Related products and manuals for Control panel Allenheath PA28