Digital isolation between Ethernet hub and streamer

@erik_squires - I agree about surge protection.  Unfortunately, outside of a Belkin unit in my server/IT room, and my Isoclean Power A60 that filters all of my front end stuff in my system room, I don't really use it.

When I mentioned isolation for purposes of this discussion, I was talking about as provided by all the small boxes that are available to purchase.  Since running optical from my server room directly into my Sonore Sig Rendu SE Deluxe, none of the other stuff has done a thing for me.  I do use an optical break (2 converters and two LPSs) directly out of my router, and then after the server, I use Sonore's opticalModule to convert the Ethernet output into a fiber optic output that goes into my system room and into the Sig Rendu SE...

@mitch2 If you are already running optical there's very little you can do to improve upon that.

@audphile1

Unpacking your username, I see you love AUD. So do I, but I just can't get enough!

Do I understand correctly that you have a WiFi mesh router about 1 metre from your system?  And you claim it produces near zero RFI and EMI?

Surely the whole reason for having a mesh router is to blast the area with G-Hz WiFi signals?

When my partner moved her business into 'legacy' premises, wiring was going to be an issue so we (?) decided to go wireless for almost everything, including Voice over Internet Protocol (VoIP) phones.  In the end, we needed two mesh routers to boost the WiFi coverage.  These mesh routers get their packets via Ethernet cables.  They also get their power over these same Ethernet cables, injected as it happens though little wall warts which no doubt have switched mode power supplies.

Always suspicious the phones might not be working properly, she would often dial her business from her VoIP phones, not realising the VoIP system was smart enough not to route the call externally!  But then, a single unanswered call could cost her AUD 10k

No @richardbrand you misunderstood me. The EERO mesh node produces a good amount of EMI and RFI. The location where it is parked prevents it from interfering with my components and cables. I use an EMF meter to position components in such way that the EMI is minimal or nonexistent around and between the components and cables in my system to the best of my ability working with what I have. 
You hold a lot of knowledge and experience. But see, the way you come across is I’m beginning to build a perception when I read your posts that you think that everyone here is a moron. You need to rethink this approach. Most of us here have been at it for quite some time. And our systems are assembled based on research, knowledge and experience we accumulated over the years. Hope this helps clear at least some of the misconception you arrived with.

@audphile1 

Thanks for clearing that up for me!  You did originally post 'near zero' but now it is a 'good amount'.

My partner really believes there are four types of matter: electrons, protons, neutrons and morons.

By and large, we 'audiophiles' are a pretty gullible lot!  For fifty years we have been fed that digital sucks. Most audiophiles stick with two channels, 25 years after multi-channel came out. Then we discover that for two decades almost all records have been mastered digitally!  And those same record-loving folk now laud streaming, which is digital, even if done badly.

I wish contributors would back up claims of clear audible differences with a bit more evidence.  How hard is it to get somebody to switch a power cord while recording what they have switched and whether you think the sound is better, worse or the same?

I tried measuring the effect of lifting my dustcover and surprised myself with the lack of attenuation of pink noise, compared with white noise.  There could be a sensible debate there