Happy to be corrected as my understanding of these things is limited. I think the white box/plug is a TP Link wifi extender, I think also known as a travel router. I don’t think the internet signal is sent over the mains, rather it is a device that receives and boosts a wifi signal. (That’s a lot of thinks because I am guessing).
When I first bought my Melco I was told that a powerline adapter was needed, two units that plugged into the mains, one connected to the router, one to the Melco. The only thing was it interfered with equipment in my attached neighbours home, so was sent back and swapped for a single plug in unit similar to the one shown. Also guessing, given the size, it contains an SMPS which may not be beneficial, but not as bad as the two piece setup.
A fond farewell I’m sure @Thomas . I’d missed that you were also changing speakers. What have you chosen to pair with the Soulution’s?
Thank you @KJC 
I’m not completely leaving the brand, I’ll probably buy a MuSo2 for my young daughter.
As for the speakers, I chose the Magico M2.
The S3 MkII are amazing speakers and, in my opinion, outperform all the speakers I heard at similar price.
As good as the S3 MkII are the M2 are in a different league.
Hard to believe or describe, really. It has to be heard and compared with other speakers (in the same environment).
Nice setup Thomas I am going for vicoustic diffuser panel after Christmas the multifuser 32 for back wall. I think they look the best made.
Next Test: Geithain ME110
Thx to the dealer in Düsseldorf for the possibility findig the best speaker for me
Lovely system & interior, and also nice to see a Starck fan too 
Thanks @Hawkmoon 
Vicoustic products are amongst the very best in terms of finish and overall build quality. You can’t go wrong with them.
However, be careful with diffusion. It would be best to have a certain distance between your ears and the diffusion system (~ 2 meters), and you’ll need a lot of surface to make a noticeable difference (I placed 9 panels in my front wall). It has a cost…
Also, check the frequencies you wish to hit. The Multifuser 64 hits lower frequencies significantly more. It is 50% deeper than the Multifuser 36. That’s why I chose the Multifuser 64.
On my back wall, I have absorption, a lot of absorption!
The combination of the front wall that absorbs low frequencies and diffuses in between speakers and the back wall that absorbs down to 50-60 Hz is pretty effective at letting my speakers do their job.
But I have plans for the future in terms of room treatment, it’ll be big! 
Next and i hope the last test will be
Audio Physic Classic 25
Spendor A7
PMC
Neat
isn‘t possible here. And without testing in my room i don‘t buy a speaker
It’s been a bit of a challenge to rearrange things to avoid hum on the phono input but I seem to have managed it. The Naim tuner needed to be moved away from the new Aria but surprisingly looks ok on the top of the rack. The bird says hello to @Cledi13 ’s.
Thanks I will be starting with 6 panels at the wall behind the Listening seat which is 11 feet away, and start with 2 panel front wall and see how it goes from there. 
Is that what that is though? Isn’t it an extender? Ie Logs in to WiFi and creates it’s own network.
I thought network over mains was different
This has probably been mentioned previously but have you tried a screen or heavy drape in front of that glass door for when you are sitting listening?
No, I didn’t. But it’s not an option either, because it’s the living room and I hear it almost every day. My wife wouldn’t want to participate in something like that.
Fair enough, just wondered if a ‘pretty’ day screen that can be moved would be a possibility.
Understood. I thought it was a Network over Mains Power unit.
I still feel uncomfortable with it on the same circuit right next to the stereo
Very nice. Are you satisfied with the solidsteel stands? I am also considering a change……
Agreed. It’s working which is the first hurdle