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

@mike_in_nc the all Benchmark stack is what I am looking at (DAC 3B, HPA4 and 2X AHB2's). I just ordered JM Editions XTC2 Headphones, tuned individually to provide with similar sound charateristics of the ML 9's and the BM stack (never had headphones before). Can't wait to receive them!

@johannm yeah these types of tweaks like iFi are low cost and depending on a system can bring some positive results. The iFi filter didn’t make things worse in my setup. I stick to bare necessary minimum when it comes to network toys. I played with FMC units from amazon (I know not the best in class) and found them to be useless at best. No plans to explore better quality FMC. I dig the sound I have now - non-existent noise floor, smooth, detailed and natural. It’s important to keep all this noisy network crap like routers and switches away from audio components and plugged into a different circuit. 

I will second the fact that the better streamer and DAC [separates] will be the biggest improvement and the most costly, but do it first anyway.   Then do your tweaks.  Smoothlan works like it should.  Network switch from Netgear $40 anywhere is an easy  recommendation.  You will notice these improvements more if you have a revealing system.

@boxcarman 

+1

I agree to keep the digital path as simple as possible.  I feed my Eversolo DMP A8 directly from router with an above average CAT 6. Then SHORT Bluejeans XLRs to AHB2. From AHB2 to Focals 948 withe proprietary Benchmark cables. No cables for thousands of dollars but I have clean and noiseless sound.