Studio Technologies Model 42A IFB InterfaceThe Model 42A is designed to create broadcast standard IFB outputs from line level audio sources. The unit's primary application is to interface analog outputs associated with digital matrix intercom systems with broadcast IFB user devices. The Model 42A creates four independent IFB outputs. For convenience, the four outputs can be connected by way of eight 3 pin male XLR connectors; four of which are located on the back panel and four on the front.