Strange noise on Focusrite Clarett+ mic inputs

[asphaltradler]

Hey, I can't let go of this. I thought about it again and have now managed to measure and visualise what I hear .
Firstly, I switched on the -10db pad on the Behringer mics. This means that the output is even lower, but the noise remains the same!
Then I wrapped the right one in a blanket, while the "control microphones" on input 3+4 interview my partner's raven (and play no role other than to influence the terrible noise on 1/2 in a marvellous way when switching their phantom power):


So now the effect is there almost without any room influence and is clearly visible in the analysis of my DAW. If necessary, I can still upload the audio, but you can now clearly see the shift in the frequency range and overall level of noise when the phantom power on 3/4 (which are not shown here) is switched off, so that the Behringer on 1/2 are alone:

(I reduced the level of the switching click when switching off the phantom power, but else the gain of before and after is the same).

Spectroscope phantom power ON:

Spectroscope phantom power OFF:

Spectrogram showing phantom ON-OFF:

So everything should be clear now: the main part of the noise shifts from about 250Hz to 500Hz, while a whole lot of noise is added above 500 to about 2500Hz that wasn't there before. This can be seen most clearly in the spectrogram!

But do we know more now?

Not until someone else has tested it with their Clarett :-(

 

[asphaltradler]

Found an even better representation with these loudness analyser and spectrogram view. Only 2dB difference in loudness but a huge difference auditory. Soundfile now in the OneDrive, too: B5 Pad eingewickelt Phantom On-Off.flac Please say so if the link doesn't work, I'm not sure.

Cosmas