Avid Technology Digidesign USD, User Manual, Page: 85 / 96

Appendix C: Wiring Diagrams Pin Assignments 81
appendix c
Wiring Diagrams Pin Assignments
LTC
The USD’s LTC In and LTC Out connectors
are balanced XLRs with Pin 2 wired “+” or
“hot,” Pin 3 wired “–” or “cold,” and Pin 1
wired to ground (shield). Depending on
whether you are connecting a balanced or
unbalanced signal to these connectors, dif-
ferent wiring configurations are recom-
mended for optimum signal integrity, es-
pecially for long cable runs.
If you are connecting a balanced signal to the
USD’s LTC In or LTC Out connectors:
• Pin 1 and ground should be connected at
the input only (not at the output). This
will prevent ground loops between the
shield and the Pin 1 conductor.
If you are connecting an unbalanced signal to
the USD’s LTC In or LTC Out connectors:
• Connect only Pin 2 to the “+” signal;
• Connect both Pins 1 and 3 to ground at
all inputs and outputs.
Refer to the following illustration for the
correct wiring diagrams.
Wiring diagrams for the USD’s LTC In and LTC Out
connectors
-
GND
1 2
3
N.C.
Device
LTC Out
Connector
+
Balanced to Balanced Connection
-
GND
1 2
3
Device
LTC In
Connector
+
GND
1 2
3
Device
LTC Out
Connector
+
Balanced to Unbalanced Connection
GND
1 2
3
Device
LTC In
Connector
+