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

@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, 


 

Out of curosity have you tried a two prong adapter (temperaly) on each peice of equipment (one at a time) to see if you can find the culprit?

@lak 
Hi,
No, I haven't tried that. It makes me a little nervous to cut out the ground. 
But I guess I could try it. 
So, if the component with the two prong adaptor stops the hum, then I should try grounding it with another component instead? Is that correct.?

I believe so. At least you will have more information to work with and someone more knowledgable than me (like erik or others) could make some good suggestions.

Remove any incoming coaxial cables, like for Cable TV, Satellite, etc. first.