The OG COMMS Intercom unit provides a means to interface between two channels of 2-wire party-line intercom audio and two channels of 4-Wire analog line-level signals. The unit is capable of performing auto nulling for each channel with the push of a button. In addition, each of the 4-Wire input and output channel levels are monitored and displayed on easy to understand card edge audio present LEDs. With the push of a button or a Dashboard setting the unit can be a +28VDC party-line voltage power source while providing the 200 ohm intercom audio termination on both channels. The unit can also be configured to work with either RTS party-line or Clear Com party-line equipment with the push of a card edge button or a Dashboard setting. This adjusts the output gain between the party line circuitry and the 4 Wire line level circuitry depending on which type of units one is interfacing with.