[Raevennan Husbandes]

Hi, Sean and all on this post.

I had the same if not a very similar issue with my Zoom H4n and Rode NTG2.

I discovered that the high pitched noise is not present if using the AC plug as the power source.

Previously I was using x2 AA alkaline batteries.

I have not tried lithium batteries with this unit but I do intend to. I will try to report back with any results!

I hope this helps you or someone else faced with this issue.

R