Sennheiser HD400 Instructions For Use Manual page 49

Power supply for
NoiseGard™
Ground
Do not connect!
XLR-3 socket for HMEC 300, HMEC 305-C,
HMEC 322, HMEC 400 and HMDC 322
headsets
1. Connecting the headset to the on-board system
The NoiseGard™ electronics can be connected to on-board power supply systems with
operating voltages between 12–35 V DC.
Danger of short circuit!
Before turning on NoiseGard™, ensure that the on-board power supply system is
protected by a 1 A fuse.
The HMEC 300, HMEC 305-C, HMEC 322, HMEC 400 and HMDC 322 headsets are
supplied with an XLR-3 socket for panel mounting in the aircraft. The XLR-3 socket must
be mounted by a technician qualified to perform this type of installation.
HMEC 300 and HMEC 400 headsets:
Connect the 1 / " (6.35 mm) stereo jack plug for the headphones and the PJ-068 jack
4
plug for the microphone to the corresponding jack sockets of your intercom.
Connect the XLR-3 plug to the XLR-3 socket.
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