Help needed to eliminate unwanted noise from tweeter

Removing/swapping components, one at a time, you should be able to narrow it down to one faulty component. 

However, the hardest problems are when 2 unrelated factors combine to cause the issue so it could be harder to figure that out.

Removing/swapping is the path forward.

Jerry

No, the tweeter is not the issue. You said it starts when you add in the DAC. It is a problem with the DAC and more than likely it is defective. Try a different DAC if you can. Try the DAC in a different system if you can. Take it to a store and see if they will plug it in for you. 

@ellajeanelle Thanks for your insights on swapping the noisy components to no-noise outlets, that's brilliant idea to trouble shoot.  You gave me "light bulb" that the Novaris PP10 surge protector/noise filter come with 8-outlet, the "noisy" one are first row... I may look into detail if the ground/earth terminals and other (live/neutral) terminals are secured/tightened.

About the noise I described... it's like hissing sound, as I read from google, some said they are pretty normal as my amplifier has a higher amplifier gain of 28dB, my speaker sensitivity is 85dB/m... only when i step closer to tweeter, I could hear the hiss sound.

@carlsbad2 Thanks for your tips, yes, I have done that, I will do few more times to isolate/mitigate if it is due to defective unit or if it is common "leakage" electric noise, I could further check if the unit is come with three-wire though they are using IEC outlet, in some instances, some may only terminate two-wire and leave the ground/earth "floating".

@mijostyn Thanks, I will check if it is DAC defect. I don't have any other DAC unfortunately.

Don't tolerate noise...keep at it until it's gone. I use a Bryston conditioner and various noise eliminating power supplies along with worsening deafness, although that last one I don't recommend although, hey, it works for me! What? What was that? 

While I am isolating the hissing noise from tweeters from potential components. I am not sure if the Novaris Surge Protector/Noise Filter, is it a good power conditioner?  I recalled I have no such issue with my previous power conditioner of Tacima CS947 (6-outlet) , I upgraded last year to 8-outlet Novaris PP10.

Anyone has experience on the above power filter/conditioner/surge protector and would like to share your thoughts?  Appreciate