Identifying & Synchronizing Signal Phase for 60 Hz Cancellation

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To effectively cancel out 60 Hz noise from a dynamic microphone signal, an instrumentation amplifier can be used alongside a generated 60 Hz source. The generated signal must be 180 degrees out of phase with the noise for effective cancellation, and matching both amplitude and phase is crucial for optimal results. However, it is often more practical to identify and eliminate the source of the 60 Hz hum, such as grounding issues or ground loops, rather than attempting to match the signals. Using a notch filter is also a viable option for reducing 60 Hz interference. Addressing grounding and shielding concerns is essential for improving overall signal quality.
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Signal phase

To cancel out 60 hz from my signal source(dynamic mic) I need to use an instrumention amp with another 60 hz source. How would I make the generated 60 hz have the same phase as the noise 60 hz?? and also do both signals have to be the same amplitude for this to work well?
 
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You have to be 180 degrees out of phase to cancel out the waves.
 
It is usually easier to find the source of the 60 Hz hum and eliminate it than to match both the amplitude and phase of the 60 Hz to cancel it out. Look for grounds and shielding, and ground currents (ground loops) in cable shields.
 
Could you use notch filter for this?
 
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