I have a AKG Pro Audio C214 Condenser Microphone powered by a 48V phantom power device (Neewer NW-100). There is a very loud, low buzzing, the frequency of which would indicate that its AC interference.
When I turn off the phantom power device, the buzzing goes away and the mic is very clear for the short period of time before the capacitors drain. Would this indicate that the phantom power device is bad or poorly constructed? Is there anything else it could be?