SPL Frontliner Modular Recording Channel - Manual (Page 11)

11
Frontliner
Rear Panel
Connections
Signal connection
Switch off the unit before you begin the process of making the first or any subsequent
connections. Neglecting this can damage either or both your ears and your equipment.
1/4" TRS socket
The TRS socket AD INPUT 2 supports both balanced (1/4" TRS/stereo jack connector) and
unbalanced connections (1/4" TS/mono jack connector). Refer to page 13 for further informa-
tion on that input.
XLR sockets
All XLR sockets are balanced inputs or outputs. Input sockets are always female for plugging
in male connectors, output sockets are always male for female connectors. All in all a compre-
hensible principle.
Balanced connections
It is impossible to exclude all interferences when a single audio signal is transmitted.
Shielding is effective against electric, but not against electromagnetic influences. Motors,
transformers, and alternating current can always induce interferences. But even if the trans-
mission would succeed, differences in ground potentials between driver and receiver would
produce disturbances.
In balanced connections a reference signal with reversed polarity is transmitted additionally
to the audio signal through a second wire. The ground signal is routed separately through
a third wire. Input and output stages are drivers and receivers, and the receiving stage can
suppress interferences by subtracting the difference between audio and reference signal.
Unbalanced connections
Unbalanced connections from and to RCA or 1/4" TS sockets can be made without adaptors to
the balanced XLR sockets. The correct wiring is important. The diagram shows the pin config-
uration of the XLR sockets and how to correctly connect them for unbalanced connections:
Connections to RCA sockets are always unbalanced, a wiring to jack connectors can be both
balanced (1/4" TRS/stereo jack) or unbalanced (1/4" TS/mono jack). We recommend to use
individually configured cables from XLR to RCA or jack sockets instead of adaptors. You can
get cables in any needed configuration from audio dealers. With the diagram above, the
dealer can ensure to provide the appropriate cable for your application.
Input Output
balanced unbalanced balanced unbalanced
1=GND
2=hot (+)
3=cold (-)
1 2
3
1 2
3
1 2
3
1 2
3