Input connectors
The SDA 2175 has input sockets for both balanced and unbalanced signals, but only one may be used at a time. The XLR and phono sockets are internally connected in parallel, so only one set of the connectors should be connected externally. ALWAYS use EITHER the XLR inputs OR the phono inputs. NEVER use both at the same time.
Fig 3: SDA 2175 Input configuration.
Balanced inputs
The balanced XLR inputs are wired in accordance with IEC268:
Pin 1: Chassis and ground.
Pin 2: Hot (+).
Pin 3: Cold
Shell: Chassis and ground.
When the balanced inputs are used with a balanced source, the input selector switch MUST be set to the BALANCED position. The switch position can be changed with a small screwdriver.
If any cables are connected to the unbalanced inputs, remove these before the switch is put in the BALANCED position.
We recommend the use of the balanced inputs whenever possible, as balanced signals are much less sensitive to noise than unbalanced signals.
8
