Checking specs, I see that most bass amps spec out at around 1meg-ohm input impedance. One or two of the Sans Amps gizmos spec at 4.7mohm input impedance (almost 5x that of a typical bass amp). Yet, some mic preamps spec at around 640k to 750k input impedance. And some DIs spec at roughly 500k. What is the point of diminishing returns? I mean how high is too high? What differences in sound can be expected with some of these really high impedances? Obviously speaking of how this relates to passive electronics in a bass, not so much active electronics. Is it safe to assume that active electronics aren't as sensitive to input impedances? Thank you.