Buzz issue in chain

Hi,

last week, I cleaned my system and moved it 0.5m to the right.
Although nothing was added and the same cables were used, I am now facing a buzz issue.

To simplify the test, I only connected the following components.
Wall jack Power to P15.
2x M700 Power Amps connected to the P15 and connected via XLR to either the DSJ or the Nobsound XLR switch
Marantz AVR (nothing plugged in, only power and 2x RCA preout)

I already disconnected everything and tested the chain backwards.
Please see below results:

-Speakers (Golden Ear Triton Ref) and Power Amps (Stellar M700) - ok, no noise
-DSJ via XLR3 Input to the power amps - ok, no noise
-When connecting my XLR / RCA switch (Nobsound Little Bear MC3 3-IN-3-OUT XLR Balanced/RCA) -> ok when set to XLR where the DAC is connected. no noise
-When I switch to XLR input 2 on the Nobsound (nothing connected there) or to input 3 RCA (also nothing connected), I get a buzz noise, not that loud but already annoying. The audiorart XLR cable to the PowerAmp becomes microphonic. (Link 1) I can tap on it and hear it in the speaker.
-Now, I addded my AVR (Marantz) to the chain. If I connect the PreOut RCA from the AVR to the Nobsound (already via galvanic filter), the noise is getting louder. When I now power on the AVR, it is getting extremly loud. (link 2). Die volume control on the AVR has no influence
-When I put my hand on the Nobsound, the noise increases.

Only connections are the ones mentioned. On the AVR, nothing except power and PrePreout is connected.

Would be really great if anyone has an idea how to solve this.
I read that it could help to connect a gnd cable from the AVR phono gnd to either the chassis of the M700 or to the PE cable (earthing) of a Schuko power jack.

The PSA gear has 3 pins incl the green gnd while the AVR only has 2 PINs. Maybe there is a potential delta.

Link1:
https://1drv.ms/u/s!AuMMuplgCxHj5YZlptF1Qr4nbF4Fag?e=04XK5w

Link2:https://1drv.ms/v/s!AuMMuplgCxHj5YZkjx_Uoc5lhNZ98Q?e=Vyrfkh

VG
Chris

Hi I recently moved my stack from between my speakers to a position off the right near where I sit. I had a new sound that sounded like vibration or buzzing. On very close inspection, it turned out to be loose cable connectors on my Stellar Phono from my turntable. Hard to see but easily heard. I would check the tension of all connectors first. Barring that, inspect cables for damage at the connectors.

My last buzz (not counting the IPA’s) originated from a bad interconnect. Keep exploring, you’ll find it…

ok thanks.
I was able to reduce it a bit by plugging in my bluRay player correctly. (measured which one is the neutral pin and which one the live / hot one) and moving my fire TV to another daisy chained outlet.
I still have the problem that the XLR is microphonic and there is a small buzz only when connected to the AVR but much better than before.

I am now waiting for the BHK preamp to arrive. If that does not correct the problem, I will check the jensen isolator for XLR.