4 Installation and Connections
28
4.7.2. MIC OPEN
Indication on
GN 15, GN 30,
GN 50, GN 30 OC,
HM 1000
4.7.3. Defeating the
LED Ring
(not applic-
able to GN 30 OC,
LM 3, LM 3 L)
Fig. 9: DPA circuit
board
4.8. Bass Cut
the system and phantom power on.
This indicates that
the system is correctly wired and ready to operate
but NOT that the microphone channel is open.
To obtain an open channel indication, the installation tech-
nician may connect the LED ring to an external power
source. In this mode, the LED ring will light much more
brightly to draw the required attention to the open micro-
phone.
1. Unsolder the blue (LED +) and black (LED -) wires from
the DPA phantom power adapter or the female mini
XLR connector. (Not required for the GN 30 OC.)
2. Connect the blue and black wires to a power source
delivering one of the supply voltages listed in Table 3
below:
Table 3: Electrical values for external power source
for LED ring
Voltage
Required Resistance
Max. Power
6 V
390
Ω
0.1 W
12 V
1000
Ω
0.25 W
24 V
2200
Ω
0.25 W
48 V
4700
Ω
0.5 W
Remove the plug-in jumper J2 from the circuit board inside
the DPA phantom power adapter referring to fig. 9.
The LED ring is nearly invisible because its color matches
that of the case.
The DPA phantom power adapter is equipped with a bass
cut filter to minimize low-frequency noise.
To activate the bass cut filter, plug the jumper J1 on the
circuit board into the second contact as shown in fig. 9
above.