SPL Track One Channel Strip - Manual (Page 8)

8 Track One
Sockets and switches
Rear Panel
Signal connection
Switch off the unit before you begin the process of making the first or any subsequent connec-
tions. Neglecting this can damage either or both your ears and your equipment.
1/4" TRS/TS sockets
The INSTR./LINE IN socket only supports unbalanced connections (1/4" TS/mono jack
connector). All other sockets are support both balanced (1/4" TRS/stereo jack connector) and
unbalanced connections (1/4" TS/mono jack connector).
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 an audio signal is transmitted through a
single wire. Shielding is effective against electric, but not against electromagnetic influences.
Motors, transformers, and alternating current can always induce interferences. But even if the
transmission 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 also be made without adap-
tors to the balanced XLR sockets. The correct wiring is important. The diagram shows the pin
configuration of the XLR sockets and how to correctly connect them for unbalanced connec-
tions:
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