The Linkx APA-50 is a quarter rack width 50 watts advanced class D audio power amplifier as a standalone product for classroom and small systems. Three stereo inputs and a discrete microphone input, along with separate line and microphone gain adjustment, allow connection to a projector, wireless microphone receiver, and other sound sources. The energy-efficient amplifier automactically goes into standby mode if no input signal is sensed for 20 minutes, dropping power consumption to 0.8W.