1U 19" rack-mountable quad amplifier with 4 input channels and 4 independent speaker outputs. Each output can deliver up to 60W to either low impedance (4 or 8 ohm) or 100V speakers by connecting either the upper or lower screw terminals on the rear panel. An internal media player can play audio files from a USB pen drive, tune to FM radio stations or connect via Bluetooth® to a smartphone for wireless playback of stored audio tracks. A paging mic input has switchable Vox function to override other channels. 2 further balanced inputs can be selected to accept mic or line level input with switchable phantom power. Channels 1 to 3 also each have Bass and Treble controls for tone adjustment. A separate line input has RCA or screw terminal connection and, if required, can be switched to serve the internal media player. Each of the four inputs can be selected to any or all of the four output zones, each with a separate output level control and line level output for expanding to further amplifiers or powered speakers. An optional CS4 call station may be added if specific area paging is needed, providing a fully independent and flexible zoning system for background music, recorded information and announcements.