I was looking at this schematic for a two-channel audio power amplifier.
The amp supports a bridged mode by means of an XLR connector and a switch. When the switch is in the XLR position, pin 2 (Signal+) is sent to the left channel and pin 3 (Signal-) is sent to the right channel and the speaker is connected between the + outputs of the amplifier.
However, as far as I can see, there is no differential stage before the power amplification stage to actually filter any noise from the balanced input. Therefore, any noise that gets onto the input wire will be amplified and sent to the speaker.
Is this correct, or am I missing something?
Here is the amplifier in question: