I have a new tube mic and unfortunately it's power supply is the only power supply in my studio (or piece of gear period, for that matter) that introduces ground hum.
The reason I feel it's ground hum is that, well it sounds like ground hum in all its 60Hz badness, and if I have a mic cable plugged from its output to my mic pre, whether the power supply is turned on or off, it'll introduce hum. If I pull its power cable, hum gone. If I use one of those 3 prong to 2 prong ground lift adapters on it, hum gone.
So finally my question: Is there any hazard to using the ground lift adapter in a case like this? Everything in the studio is on the same isolated circuit. This mic will be used for a vocalist who will simultaneously be playing a D/I'd electric guitar, and I'm thinking there's no hazard here, but as you can probably tell by this question I've flunked grounding 101 several times and could use some reassurance.
Thanks.