DR-680 phantom power noise

I got a question whether the Millenium pp2b would be less noisier then the DR-680 phantom power.
Apparently there is something wrong with the DR-680 phantom power. I have never experienced any problems with this but we can to try to measure it.

Here is how I did it:
On one leg I connected a resistance to ground to simulate mike consumption.
On the other leg I connected a capacitor to ground. This forms a RC filter to keep out high frequency signals.

This is by no means a *real* noise measurement. The only goal is to look for differences.

I measured the DR-680, the Shure FP-33 and the millenium box using the FLUKE 45.
It is difficult to have a stable reading but the FP-33 is about 9 dB quieter than the DR-680 and the millenium box is about 11 dB quieter.

So indeed , it looks like the DR-680  is noisier than needed.

update

I posted a simple mod for channels  1 to 4.