This power supply created very loud buzzes, hums and or clicks in all of my effects peddles

I've tried the OS-2 on other power supplies alone and proved it works fine (no hum), but when I plug it into the chain of pedals without even connecting it into the Mr. Power it starts making the horrible hum again

This power supply creates a steady hum

First when I plug it into my pedalboard the amp starts having a tolerable hum

I've tried the OS-2 on other power supplies alone and proved it works fine (no hum), but when I plug it into the chain of pedals without even connecting it into the Mr. Power it starts making the horrible hum again

Power adapter has a terrible hum noise and interference permanently.

Sure it delivers power to all of my effects pedals, but now there is a steady hum when there should be dead silence