User Guide
19
Audio connections
Input
The input circuitry is a transformerless, electronically balanced design which
achieves a common mode rejection of at least -50dB from 20Hz to 10kHz.
If transformer balancing of the inputs is required, this must be stated at the time
of order as they are not retrofittable.
Output
The output circuitry is a transformerless, electronically balanced design
which achieves an input rejection of at least -65dB from 20Hz to 10kHz. The
output is capable of driving +21dBm into a 600 ohm load.
If transformer balancing of the outputs is required, this must be stated at the time
of order as they are not retrofittable.
Balanced Circuits
Transformer or electronically balanced connections have the benefit of
Common Mode Rejection which eliminates externally induced interference such
as mains hum etc. Balancing is especially useful when long cable runs are used
between pieces of equipment.
Transformer balanced circuits have the added advantage of being fully floating
with the ground (earth) or screen being totally isolated from the signal. In
installations where a difference in earth potential is likely to occur, this isolation
prevents grounding problems which can in some cases damage the equipment.
XLR Pin Connection (Input and Output)
Pin 1 Ground (Earth)
Pin 2 Signal
Pin 3 Signal
Unbalanced
For unbalanced operation, connect Pin 2 to Pin 1 only on the inputs/outputs
which are being run unbalanced.