Manual

8
Audio Connections
All analog XLR audio inputs have a nominal level of 0dBu (full scale +20dBu). AES3 inputs support 32, 44.1, and
48KHz sampling rates. AES3 inputs are only provided for FEED/IFB ports 1 and 2.
Analog input pinouts:
Pin 1 Ground
Pin 2 Balanced audio +
Pin 3 Balanced audio -
AES3 input pinouts:
Pin 1 Ground
Pin 2 Data +
Pin 3 Data -
Contact Closures
Contact closure signals are available via the male 9-pin D connector on the back of the EarShot IFB. Inputs are
triggered by shorting the respective input to Pin 5. Outputs consist of an open collector circuit which, when inactive,
will offer a high-impedance path to Pin 5 and, when active, will offer a low-impedance path to Pin 5. These outputs
are capable of sinking up to 200mA at a voltage up to 12V. Do not switch AC mains power using these contacts.
In current firmware, only the four CC outputs are utilized. These outputs are triggered whenever a call is assigned
to a numbered feed. E.g. if an incoming call selects Feed 2 option, CC #2 will close for the duration of the feed.
Contact Closure Pinouts:
Pin 1 Input #1
Pin 2 Input #2
Pin 3 Input #3
Pin 7 Output #2
Pin 8 Output #3
Pin 9 Output #4
Pin 4 Input #4
Pin 5 Ground
Pin 6 Output #1
Connecting Up EarShot IFB
At a minimum, EarShot IFB will need one audio connection and a network connection. Levels of all analog audio
I/O is 0dBu (0.775V) nominal. This level will provide 20dB headroom before the clipping point. Input audio is
reflected on the front panel LED based peak meters as indicated in the figure below. Clipping is indicated by the
red LED on these meters.
EarShot IFB needs a network connection to be useful. On EarShot IFB, network connections are made via a
standard 1000Base-T Ethernet connection on an RJ-45 connector.