Do I need a remote wire from head unit with no amps in use? Need to bypass amplifire

 

I do not see any circuitry here that could function as either a pre-amp or output amp. What i do see, is a simple power supply consisting of a transformer, a full bridge rectifier and some filtering capacitors. The rest is just connectors and what looks like a mono/stereo selector switch with some resistors for passively mixing the left and right channels into mono.