GL2200
U
SER
G
UIDE
7
An external DC supply may be used instead of, or together with the internal supply. Use only
recommended Allen & Heath power supplies or a supply approved by Allen & Heath. The use of
alternative supplies is not recommended and may cause damage.
The pin connections for the
EXTERNAL DC IN
connector are specified below:
In the absence of an active 100V to 230V a.c. mains supply, the
GL2200
will automatically switch over
to the external DC supply unit if connected.
Always turn connected power amplifiers down or off before switching the console on or off.
EARTHING THE AUDIO SYSTEM
The console chassis is connected to mains earth via the power cable. Audio 0V is connected
internally to the chassis and therefore mains earth. In this way all signal returns and connector shields
are connected to mains earth at the console.
For best performance it is important that the earth system is solid, clean and noise-free. To prevent
mains-borne and external interference pickup from lighting equipment, motors and other mains
powered equipment it is recommended that a separate ‘clean’ mains distribution outlet is used for the
audio system.
All signal cables should have their screens connected to earth at the connector. If earth (ground) loop
problems result in audible hum or buzz then disconnect the cable screen connection at one end,
usually the destination end. This may be done within the cable plug or by operating the ‘ground lift’
switch if available on the connected equipment. Many DI boxes and power amplifiers include this
facility.
Pin Voltage Current
1 -16V 1.5A
2 Audio
0V
3 Chassis
0V
4 +16V 1.5A
5 +48V 0.1A
In the event of an electrical storm, or large mains voltage
fluctuations, immediately switch off and disconnect all power to the
console.
To ensure safety, do not remove the earth connection from the AC
mains plug or from EXTERNAL DC IN cable.
