The AA100PHD is a four input channel mixer amplifier designed for distributed business paging and background music (BGM) systems, small to medium speech privacy systems, and in applications where music on hold (MOH) plus paging is required. With one microphone/line input and two stereo line inputs, the AA100PHD will accommodate a variety of input sources including paging microphones, media players, and digital music receivers. What Sets the AAPHD Series Apart?The AA100PHD includes a patent pending automatic system test, the Push Here Diagnostic® (PHD). The PHD button is designed to check the connected loudspeaker lines for wiring and impedance errors. This test can be activated once all loudspeakers are connected and the circuit automatically verifies that the attached loudspeakers' tap settings do not exceed the amplifier's rated power, no loudspeakers are mistakenly tapped at 8?, and the loudspeaker wire is free from shorts.The unit also incorporates a Remote Input Selection and Remote Level Control feature that allows the integrator to use a remote wall plate (AtlasIED model WPD-RISRL) and allow the user to select the input and adjust the volume from that wall plate up to 200 feet from the amplifier.The AA100PHD provides 100-watts output power into 25V, 70.7V, or 4? loudspeaker systems. Rear panel DIP switch allows for creation of Zone 2 output/output mix using any or all of the four inputs. Unit can also be set-up to mute Inputs 2, 3, and 4 based on signal from Input 1 for paging applications where other input sources need to be muted during a page. Input 1 and Input 2 are either Mic or Line input selectable and Phantom Power is an option when using either as a mic.