Sadly I'm from Europe so I don't think I'm going to take up on that advice, but are you saying T-Powered mics can be more troublesome than P48 ?
I have tried the microphone on another preamp and other microphones on the preamp, and have concluded the problem lies in the 416.
And the spectrogram shows the noise is nowhere near as evenly distributed... there's a lot more noise above 10kHz, which I think indicates some form of anomaly going on...