9762A
– Preamplifier
Owner’s Manual
Page 5
RTZ Professional Audio
3.3
Module Connections
Install the module in a 500 rack (always with the rack powered down)
and verify that
the XLR input and output cables are connected properly.
In some cases you may wish to lift the ground wire from pin 1 of the
output signal
XLR cable to “float” the ground and create a “telescopic
shield”. This method provides full ground loop isolation since the 9762A
is fully transformer isolated.
The 9762A is designed for balanced mode operation as typically found in
professional studio installations. While it can be wired for unbalanced
operation, we highly recommend using balanced mode operation for
reduced hum and interference. If you must wire the unit for unbalanced
operation, keep the cables as short as possible. Connect pin-3 of the
rack output signal connector to ground for unbalanced operation. Note:
the transformer coupled output means that you MUST connect pin 3 to
ground for unbalanced operation.
It’s best to carry pin-3 all the way to the
unbalanced input and ground it there.
Power up the rack after all the I/O cables and connections are properly
established. The 9762A VU and signal LED
’s should illuminate when the
rack is powered up. If the LED
’s fail to illuminate, check that your
mainframe has the c/- 16V power and that no fuses are blown.
Table 1: Edge Finger Pin Definitions
Pin#
Description
1
CHASSIS GROUND
2
OUTPUT '+' (+4 dBm)
3
N/C
4
OUTPUT -' (+4 dBm)
5
AUDIO GROUND
6
N/C
7
N/C
8
INPUT '-' (+4 dBm)
9
N/C
10
INPUT '+' (+4 dBm)
11
N/C
12
+16 VOLTS DC
13
POWER GROUND
14
-16 VOLTS DC
15
+48 VOLTS DC