Preamp, Class-D, and LPF

Fig. 1: Schematic of communications link

The XLR connector allows us to connect the microphone's output to our preamplifier circuit. This preamplifier was designed and built by our Electrical Engineers using discrete components. The preamplifier's signal is then fed to the Maxim Class-D amplifier. The output is low-pass filtered and delivered to the speaker.

Because we are not transmitting our signals in stereo, we will have the ability to utilize the unused channel of the Class-D amplifier for the opposite transmission path. This general schematic represents both the inbound and outbound communications link.