One issue -- a popping sound as I'm taxiing and during takeoff. Don't
hear it again, but every flight so far, popping.

There's also a whine once in a while which I think is the final approach
of the ILS but it's been happening in other locations.

The only popping noise I hear is when I've got the canopy open, the wind
from the propblast tends to push the headphones off their seal a little bit
which causes a sort of a bleet from the ANR circuitry.

As for the whine, any chance your alternator/battery is a little weak at
low RPM's. With everything on in our plane, the we picked up of a
whine at extremely low power settings (it's in the intercom actually,
not the heasets themselves).