Polycom Vortex EF2241 Application Note page 29

3. Connect the auxiliary line level output of the codec to one of the line level inputs of the Vortex
device (Inputs A-D). You may use one of the Mic/Line level inputs, but you need to disable all
processing on that input (AEC, AGC, NC, Automixer), disable Phantom Power, and set the input to
line level versus the default of mic level.
Follow the diagram below to make the proper physical connections to the codec. Do
not use any other audio inputs or outputs as they could cause an audio loopback to
occur within the codec.
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