I've tried my old Sansui Au-717 amp on the wall socket, and there is only the DAC and the DSP on the PSM-156 and the hum sound is gone from the speaker, not from the DAC transformer but I don't hear into my listening position. So I think it's not a DC problem, but a ground problem from the...

I have the PSM-156 and the ground master city hookep on my system and the sound is better overall, but my DAC that is an Ares 2 as a transformer hum when connected on the PSM-156, or without the PSM. I've tried a ifi DC blocker on my DAC and it doesnt reduce the humming coming from the Ares 2...