Ground Loop Hum caused by hardwired AC MAINS FILTER - help needed

I could be wrong but looking at this product I fail to see how it will prevent ground loop hum.

Hello @lak 
Thank you for your reply.
I was wondering if it has the potential to cause a ground loop. I remember reading sometime ago that if the earthing of the unit was done a certain way, then a ground loop could be formed.
Thx, 

Wait, so you are saying that the ground loop is happening on a circuit that is not protected by this device??

@erik_squires 
@lak 
I thought the hardwired filter may have been causing a problem.
Today I had an electrician (lived close by) who popped by. He disconnected the filter/surge protector in the electrical box.
I turned on all the audio but alas, it still had the buzz. I asked him just reconnect the filter again. 
So, at least I know its 'not the filter'. 

I have swapped all my components (except power amp) and still the buzz is there. That means it must be the power amp.
I will start another thread in the amp/preamp forum. I have photos of my amp and a short video of the system and buzz. I now suspect the problem stems from a Ceraphim capacitor (power) I had installed a while ago. The cap value may not be matching.
TBC...
Thx,