Hiss not Hum help

Hi all,

I have been on my "audiophile"  journey for several years and my main goal is to reach great instrumental separation and clear voice with a wide soundstage.

I mixed and matched many brands such as Anthem, Onkyo, Parasound, Emotiva, Furman, APC, Audioquest, Kimber Cable, Oppo, Ifi, and even DIY, and in general, liked the sound of the latest system, however, there is a hiss coming out of any tweeter, and overall for music is fine since I am 10 feet away from my front towers but If I turn on the Home theater the aggregation of all speaker makes the hiss unbearable.

My attempts to solve the "problem"  include replacing receivers and preamps like switching from Onkyo to Oppo network streamer and recently to Anthem AVM60, and also from RCA to XLR cables, which I used basic cheap RCA, to AudioQuest Red, Acoustic Research Master series, and currently Mogami Gold, cables and cable type made no difference.

On the power line, I started with a regular cyber power AC filter, moved to an APC H15 AC filter, then a Furman Elite PF15, and also tried an Emotiva CMX2 and an Ifi AC purifier, all of this made little to no difference.

Does anyone here experience similar hissing, and has any budget suggestions to attempt to solve this issue?

thanks for everyone's help.
I once had a hum in my tweeters.
I placed a ISO-MAX ´´  2 channels  line input  isolator ´´ between the HT processor and the power amplifier and the issue was solved.

"Your system has too much gain in the chain."

+1. It is most likely the preamp that's adding too much gain.
The "hiss" problem is usually because of a preamp that has an extremely "high gain" stage combined with ultra-efficient speakers.  I'm not sure that your Focal would be considered ultra-efficient.  These are typically the really high 98-99db speakers such as Tekton or Klipsch. 

I'm also wondering why you would get this hiss problem from the Anthem AVM60.  Typically these HT processors have a resistor ladder volume adjuster on the output which would reduce any hiss as you turn down the volume.  I would almost think something is wrong with the AVM60.  It's too bad you don't have the ability to try a different preamp.

You could try getting some RCA or XLR attenuator adpaters to put between your AVM60 and the amplifiers if you wanted.  These will drop the signal level going into the amplifiers by something like 6db or 9db.  I cannot guarantee that this would solve the problem, but it is something that people do when they have an ultra-efficient speaker.
I went ahead and ordered some ground isolators, transformer isolators, and also attenuators, let's see which one works best and I will post results here.