After considering my options and needs, I concluded that I will sell the Reference 7.1 DAC and keep the R26. This leads me to the obvious question:
How to maximize the performance of the R26?
I am looking for suggestions within a sensible price range like $100-200.
If we assume that the best input is the LAN port, given the data transmission is cleaned up, then I would like to get some specific advice (links or at least the full name on items) on how to isolate electrical noise from the Ethernet.
My speculation in this context is that gadget types like the Ifi LAN iSilencer may do a good job, but they apparently don't eliminate the noise issues completely. Is see that some recommend having two such LAN filters, which to me indicates that such units don't remove noise 100%. There is a reduction, but not a full elimination.
Instead, it would be better to get something that completely removes electrical noise from the line, like getting two fiber LAN converters (converting copper to fiber to copper) since the fiber only carries the data and won't carry noise, if I understand this correctly.
Another way to do it would be getting a separate Wi-Fi repeater or access point (?) with a LAN output which then is connected to the DAC with a regular copper LAN cable. However, I question whether the second option is as bullet-proof as the first one, since the repeater or access point may create some noise of its own...?
A third and easy way to eliminate computer noise getting into the DAC was mentioned by Currawong in his YouTube video: Simply use the optical input on the DAC. However, years ago I read that the optical digital connection is the poorest and generally should be avoided when playing hi res music. This may be wrong or technical advancement in DACs may have made this claim obsolete.
I should add that I have in fact tested the optical input using my Squeezebox Touch and it did sound nice. Whether it was better or worse than via LAN input is another story. I haven't does a side-by-side test of these two, and for obvious reasons, not with a notoriously clean data connection into the LAN port.
To me, the idea of going the fiber route seems like the safest bet and won't cost a fortune (which is important). I'd love to see some experienced/knowledgeable suggestions.