I ONLY use batteries with my Zoom H2. I’ve not experimented with the AC adaptor because I get 3 hours or so from a set of batteries and that pretty much covers my production audio needs powerwise. I imagine any available plug can present ground loop problems bringing on the hum/noise. And, it is possible that some church events could exceed 3 hours. On the occasion when I’ve needed extended recording time, I have the advantage of owning multiple H2 units and simply can start up a second unit, or if an event lull takes place, replace the batteries and card in the initial unit and restart. I’ve never, however, had to resort to the AC adaptor.
I expect you’d need some way of testing the outlet to ensure it is clean for AC use before taking a chance with any plugged in device as this problem can be consistent or intermittent depending on the facility electrical wiring conditions.
