I also own an Atom and would recommend the same path @frenchrooster suggested with some modifications from my experience. The Uniti Atom has a high potential and a comparison with the Nova brought an improvement, but it was rather small for the extra price in my opinion. With Supernait 3 + NDX2 many here on the forum have had very good experiences, but the set is in a different price range. If you have a limited budget, I would recommend:
- Powercord: Vovox Excelus NEMA version (neutral and dynamic). Massive, instantly audible sound improvement compared with the „poor“ standard powercord ot the Atom. It is half the price of the rather expensive Naim Powerline.
- Isolation Shelf: there is no offer from Naim for the Uniti line. I built mine myself following Xanthe’s instructions here on the forum (Link: Click here). Again, the sound improvement was massive (this was also experienced by others on the forum).
- Audio Power Block: I use Furutech e-TP60E NCF, which I bought used. It is good, but there are also good alternatives here.
- Audiophile Switch: I did not believe it for a long time, but network optimization is very important. I use Silent Angel Bonn N8 switch with success. Others use English Electric (Chord) switch or Upton EtherRegen switch with good results.
The Uniti Atom sounds now very much better compared to the beginning (out of the box). Everything has paid off. The Atom thanks an optimized environment with a massive sound increase. If you like, you may have a look (Click here). Enjoy the music and your system.