Abstract: An audio mute control signal generating circuits uses a high gain differential amplifier that switches transitions at the zero-crossing of the input audio so that the clock for a mute enable circuit is more readily controlled. The high gain differential amplifier includes a modification to a conventional type first operational amplifier in a cascaded operational amplifier configuration wherein additional cascade feedback transistors are added in parallel with differential output transistors from the first stage and are connected to an input stage of the second cascaded operational amplifier. With this configuration, when the output common mode voltage drops, the channel conductance of the cascade feedback transistors increases to oppose the change thereby increasing the common mode voltage to a suitable level so that the second stage does not inadvertently shut off.