Allen&Heath GL2800 - Manual (Page 39)

GL2800 User Guide 39
Output balance options
The aux and matrix
outputs are impedance balanced as standard
operating at nominal -2dBu and with +20dBu
maximum drive. They provide similar interference
rejection to electronically balanced outputs when
connected to balanced equipment inputs. An
electronically balanced option is available if you
require nominal +4dBu and higher output drive up
to +26dBu over very long cable runs. However, it is
not usually necessary to fit this option as the
impedance balanced drive satisfies most
applications. Check that you really need the option
before fitting it.
There are two balanced driver ICs which may be
used. Either is suitable. These are available from
Allen & Heath or good electronic component
suppliers. The Allen & Heath part number is shown
below:
SSM2142P A&H Part AE0302
DRV134 A&H Part AE5725
For each aux master, snip the legs of the two zero
ohm resistor links next to the IC socket. This
removes them from the circuit. Now simply plug the
option IC into the socket. Observe the correct IC
pin1 orientation and make sure its legs are correctly
aligned with the socket. Test the output once the
work is complete. You should measure the same
level but opposite polarity signal between + (hot)
and ground, and – (cold) and ground.
Sys-Link V2 input/output option A blank
plate is fitted in both positions as standard. This
may be replaced with optional cards which provide
the console inputs, outputs and PFL system on pairs
of 37way D connectors for linking to other Allen &
Heath consoles already fitted with Sys-Link V2. The
GL2800 can become an input channel expander
(slave) or have its number of input channels
expanded (master) when linked to other consoles.
Two 37way cables are required to link the
GL2800 with another console.
The 37way shielded multi-core cable carries the
balanced, line level mix signals and PFL/AFL system
to or from the other console.
IMPORTANT: Note that you need 37 to 25way
adapter cables if you are connecting Sys-Link V2
(Version 2) to the older Sys-Link V1 (Version 1)
standard.
For full details please refer to the Sys-Link option
Applications Note AP6284 and Fitting Instructions
AP6159.
SLAVE CONSOLE
A
SYS-LINK V2 OUTPUT
SYS-LINK V2 INPUT
MASTER CONSOLE
B
A B
37WAY CABLES
U5
R102
R103
R5
1 U5 R5 2
R5 2
R5
1
R8 3 R8 2
U5
U9
R170
R 169 R168
R167
U1
5
U1
4
JP 2 JP 1 OF
F ON +4
8V
GROUP 1&3
GROUP 2&4
GROUP / MTX
MASTER L
AUX 10
BALANCE
AUX 9
BALANCE
AUX 2/4
BALANCE
AUX 1/3
BALANCE
MATRIX 1-4
BALANCE
AUX 5-8
BALANCE
TB MIC
+48V
AUX 1-2/9-10
PRE/POST FADER