I am wanting to buy a mic pre-amp, but I am running into the problem that the mics that I use run off of a battery source which will not let me run 48v phantom power because it could over power the mic (from company rep). I need to find a pre-amp that has switchable phantom power option. I have wanted to buy a used oade mod ua-5, but I believe that it does not have switchable phantom power. Iwould like to get a a/d coverter/ pre-amp in one unit. Cost considerations $500 or under. Need advice on what I should get? Any help would be much appreciated.