Is there a way to electronically modify the SM57 to reduce the amount of noise it outputs? All of my 57's hiss and have a "hatching" buzz in them (not 60 cycle)
The SM57 is a dynamic microphone, and thus does not have any active electronics in it. The SM57 is simply a voice coil and transformer. The noise output of dynamic microphones is essentially zero, the same as a resistor. This is much, much less than the noise from the input circuitry of a mixer. If you are having noise problems, you should check the cables and mixer.