I have a Sennheiser MKH 815T rifle mic which I will be selling on behalf of a friend. This mic dates from the sixties or seventies, and was popular for use on location for various purposes. It is powered by a T-Power 12 volt supply, but I don't have one and therefore cannot test the mic, other than to say it was OK last time it was used. T-Power was superseded by phantom power long ago. I have a mixer with standard 48v phantom power, but not 12v. I have discovered where I can hire the correct supply, but as the mic is not mine I'd rather not incur any extra cost at this stage, so I wondered if anyone here knows how I could rig up a temporary 12v supply, connected via the XLR cable connection just so that I can test the mic?