Just to clarify, higher preamp voltages do not "minimize" the source of noise. Higher preamp voltages increase the signal to noise ratio (SNR).....the level of the induced noise is the same, but the level of the signal is higher so the SNR is also higher. Saying the noise is minimized implies that the higher voltage has some inherent ability to "reject" some of the noise, reducing it's level....which it does not. The noise is the same, but the SNR has increased.M5's point was that in the cases where you have an audible amount of induced noise, the problem is the signal cables or routing near sources of noise in the vehicle (which does not include the amp's power cable), and increasing the voltage of the signal is masking the problem rather than fixing it.