I have this power supply for some months and I am absolutely satisfied.
Purchased 69 Euros Thomann it feeds my 5 pedals.
Like everyone else I was using a conventional power supply 9v (Boss) interference occurred to me that I clenched the highest degree!
Since then, no more ringing, everything is perfect.
This power supply is very well designed (see site for technical explanations).
It has six outlets and two 9V outputs adjustable from 6 to 12V. It is powered from the 230 sector by a small transformer (supplied) which was released in to the 15V power supply.
A small batch of cables is provided in different lengths, to power the pedals.
This device is very well designed and seems solid.
I highly recommend to anyone looking for a good power supply reasonably priced, excellent quality / price ratio!