These are automatic microphone switching units, that sense the presence of someone in front of the microphone. Equipped with an infra-red sensor, the units plug between the microphone and microphone connector.
The Optogate unit switches the microphone on when someone is in front of it, and off again when they are no longer there. A red status LED indicates when the microphone is switched on. They help eliminate unwanted background pickup by unused mics on stage, and reduce the possibility of feedback.
The sensitivity is adjustable via trim pot, so can be set for optimum operation for the type of application – for example close-mic music vocals will benefit from a lower setting than conference sound reinforcement applications. All Optogate models are powered from 48V phantom power, no AC adapters or batteries are required. Inputs are XLR 3-pin female, outputs XLR 3-pin male.