Hello, I'm needing to send an intercom signal from a lobby to one of eight different rooms. I am creating a touch-screen interface with a Raspberry Pi under the hood that acts as an intercom. The user needs to be able to select any room they wish to speak to (even all of them at the same time). The receiving end is a LE-D Airphone intercom substation: Manual http://www.aiphone.com/home/assets/...s/products/instructions/LE-D, LE-DA Instr.pdf I'm going to use the Raspberry Pi to accept and amplify a microphone signal before sending the signal out through the 3.5mm output port to a splitter of some sort. Are there any devices I can make or buy that would do this?