Not sure of the best forum for this, so will start here.
I recently recorded a woodwind quartet with two sets of stereo mics as follows:
AKG C414B > SD 744T (inputs 1 & 2)
AKG CK481 > lunatech V3 > SD 744T (analog audio inputs 3 & 4)
Usually, I power the lunatech with a DVD battery. This time, since I knew I would be near power, I used a wall wart that I got from KindKables to power the lunatech.
It seemed strange to me that I got a 60Hz hum on inputs 1 & 2 on the SD 744T and not on the lunatech signal path.
The hum occurred both at the recording location and subsequently at home.
I checked all other possible sources of the hum, and it is limited to use of the wall wart.
Using the same setup with DVD battery power, no hum was present.
Any ideas how to resolve this (other than the obvious -- battery power)?