What cause tweeters hiss ?

@itsjustme @perazzi28 @oldrooney @gs5556 @jb1 @clearthinker @erik_squires Dear all, thanks for your advise and sharing thoughts.

Finally I have discovered the culprit, it’s my 15 years old Cardas XLR interconnect. (even I have had tried phase invert at both Ares II and E280) .

After I replaced with a normal decent Ugreen XLR interconnect. No more hiss on both tweeters.

Should I get a better XLR interconnect?

@perazzi28 all high-end audio equipment here are 3-pin UK with ground connected and with IEC 60320 C13 power cable.

Interesting.

So premium interconnect can worsen SQ as well as improve it!

@auronthas I’m glad to hear you solved your problem. Getting a better interconnect is up to you. The purpose of spending more money is to get better sound, and to give yourself peace-of-mind that you’re doing everything, within your means, to achieve it. 
 

I would be interested to learn more about the XLR cable you replaced. Have you opened it up to check its connections? One of them could be loose or the victim of a cold solder joint. A poor connection would, I think, add a great deal of capacitance to the line.
Have you checked the cable with an Ohmmeter? I have found pin 3’s (ground) and even pin 1’s (opposing signal) tied to the XLR shell’s tab, sometimes at both ends. Pin 3 (ground) should only be tied to the cable’s shield at one end if it is to perform its proper function. If it tied to ground at both ends it is no longer a shield, but a conductor, connecting one chassis’s ground to another, or even connecting signal ground to chassis ground.
I think I’ve read, on this forum, that the connection should be made at the ‘male end.’ Which begs the question, for me, if it is the XLR connector or the actual pins which are referenced. The male XLR connector houses the female pins; whereas the female XLR connector houses the male pins. The male XLR connector plugs into the ‘source;’ the female XLR connector plugs into the ‘destination.’ Others on the forum have recommended ‘grounding at the preamp,’ which is the destination for an analog source or a DAC; but a source for the amp. Perhaps someone with more insight can clarify matters for us both. 
 

Again, I’m glad you managed to solve your problem. 

@oldrooney hi, thanks for your detail explanation on the XLR pin terminals construction,  i am not electronic savvy, and furthermore this XLR interconnect may have reached its life span after 15 years ? I will leave it, lucky that I have a spare XLR that connect to my headphone amp. Temporary this will replace my old Cardas. Thanks again.

Unspecified, but i will assume that this is the XLRs (balanced cables) between your DAC and integrated amp? Therefore analog.

Yes, unless there is some major defect in the XLR cable, this really makes very little sense.  I have seen, very occasionally, that when a ground is lifted or weak, rather than simple hum (60 Hz, 120 for rectified power) there can be a complex noise that includes higher frequency stuff. So maybe, just maybe the XLR ground is damaged (broken).  This raises a simple way to triangulate is it one or both tweeters? If BOTH then it would have to be both XLRs - which is unlikely.

I don't think you have found the true culprit yet.