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

@mclinnguy My dealer brought a couple of these to audition. Its been a couple of years-Nordhost and maybe Melco. So, I'm pretty sure the setup was good. I just didn't hear any improvement which disappointed me-I was prepared to buy.

I respect that some have a different experience. That's only natural. Which gets to an issue that arises with a lot of forum advice. I can say for sure on the day I tried this gear that in my room, with my equipment, I didn't hear a difference. I don't extrapolate from that fact that switches can never make a difference. I think anytime someone makes a definitive, purportedly universally true statement. e.g., CDs are better than streaming, vinyl is better/worse than digital, tubes are better/worse than ss" its time to get a big grain of salt and be very skeptical. This is very subjective, we all hear differently and have different preferences. 

Otherwise, there would be a lot fewer brands. So, advice can point in interesting directions, but no one can definitively tell you what will sound "best" to you. So, in the end, you get a lot of honest advice that goes in opposite directions. It can be thought provoking and helpful, but rarely definitive. Listen for yourself, if at all possible is always good advice.

@kerrybh Thanks for filling in more details. 

Listen for yourself, if at all possible is always good advice.

Absolutely, beyond our ears and personal taste, my belief is we all have different qualities of power and internet entering our hifi, so if no benefit is perceivable spend the money somewhere else. 

kerrybh

. . .  but no one can definitively tell you what will sound "best" to you.

+1    Everybody’s system is different.   

The goal is to address Conducted EMI - and - Radiated EMI.    Fortunately, there are multiple solutions.   Whichever one works best for you - is the right one for you.

@mclinnguy, good point about his system photos which indicate a system capable of revealing differences. The point I was trying to make is that regardless of the quality of the switch, audiophile or not, that unless the last bit of cable is unshielded the noise (EMI/RFI) is allowed to travel along a conductive path and pollute the analogue side of your DAC. Sure, a better quality switch with more attention paid to the ingress of noise will bring better results.

@kerrybh, the dealer who brought you some quality switches to audition might not have fully understood the importance of using an unshielded cable as the final connection to your system.

I only suggested the inexpensive switch and cable as a quick test to see if you notice any improvement. If your dealer was unaware and used a high-end audiophile Cat 7 or 8 shielded cable, the switch's benefits wouldn’t be evident. I’ve encountered dealers who are unaware and just trying to upsell as much as possible. That said, I don’t know your dealer and mean no disrespect.