Do upgraded LAN cables/purifiers/switch box make a difference. What is recommended, if so?

@strawj thanks for the input and experience. Heard a lot about BJC - all good. Just had a quick look at the website.. For 4 cables (router>switch>streamer/AVR/STB) it will be less than a $100. This makes it a no-brainer 

(If there is another reply similar to this - apologies - Agon keep on asking me if I am human. Quite funny though - a robot asking me on a digital device whether I'm human [shrugging shoulders, as there is no emoji for it]

From my limited understanding of the digital world, those focusing solely on "bits are bits" are missing the bigger picture. While the bits may arrive perfectly intact, EMI and RFI can tag along. The ethernet cable feeding the system can be inexpensive (delivering perfect bits plus noise), but the real issue arises when the signal reaches the DAC, as RFI will interfere with the analog section, causing audible problems.

Adding a switch, such as the affordable NETGEAR mentioned, can help if placed just before and as close to the streamer as possible and connected with an ethernet cable no longer than 2ft. It’s important to use a UTP (unshielded) cable to break the EMI/RFI path. Using an STP (shielded) cable will allow noise to enter the system, which you want to avoid. A basic Cat 5 UTP cable works fine, but an unshielded "audiophile" cable combined with a better network switch, like those mentioned earlier, can further minimize noise and enhance performance.

Solid advice from earlier posts about everything mattering is worth following, as is the suggestion to address room acoustics—major improvements await with proper installation. I understand the lack of options in your area; DIY room treatments might be worth considering.

I’m based in Ireland and can recommend a good Jameson.

@gournard Thanks for your input. You clarified something that I picked up on the Blue Jeans Cable website for the first time. The difference between the use of shielded and unshielded cable. The website was a little bit cryptic and only stated "If you're wondering whether to go shielded or unshielded, the general rule is that shielded terminations are good only if your whole network is shielded ". Question nI had is; how do I know if my whole network is shielded?

Agree on the solid advice received from the forum members - How to choose between the excellent recommendations and products. My process is build around DYOR (on all the recommendations), shortlist (on various factors - value being one) and make sure it fits into a general decision-making framework that I have - small specialist manufacturers will (almost always) get my vote. 

I'm very amenable to Jameson as I am to Guiness & Kilekenny on he hops side! In fact I'll be stocking up on the latter 2 for the afternoon of 22 November. Will you be at the Aviva stadium in Dublin then? I'm sure most Irish are still feeling aggrieved by the Rugby World  Cup results. Well, I'll be wearing my Springbok jersey - but will have settle for watching on TV. Good luck though!

I'm not entirely sure about the importance or effects of shielding, but I do know that the last cable that goes from the switch to streamer or streamer/DAC should be 2ft or shorter, must be unshielded to prevent RFI from reaching the DAC. The reduction in the noise floor is undeniable

I don't know if I’ll make it to Dublin, but as a South African, I’ll definitely be cheering for the Bokke!

Need to get an unshielded cable then. 

I assumed you were Irish! Bad assumption. Then again there are so many Saffas scattered around the world - shouldn't be surprised. Half the apartment building I stay in, are fellow South Africans, mostly all pilots with Etihad (me not pilot)