Regarding my NDX to NDX 2 upgrade:
I also have the Naim HeadLine powered by a HiCapDr and a set of Focal Utopia headphones.
I could never enjoy the Focal Utopia headphones with my old set-up. Music had a harshness and an edginess that just wasn’t enjoyable. It was very fatiguing.
I had no idea what the problem was.
My source was the NDX > Naim DC1 > Naim DAC with XPS.
My interconnect was the Naim HiLine.
My preamp was the NAC 202.
I debated whether to upgrade my source or whether to upgrade my preamp or whether to shop for a new headphone amp.
I decided to trade-in my NDX and Naim DAC and upgrade to the NDX 2, and it solved my problem.
My source is now the NDX 2 with XPS, and my headphone set-up (HeadLine with HiCapDR > Focal Utopia Headphones) always brings a smile to my face. All the harshness and fatigue are gone.
The NDX 2 is much cleaner than the NDX > Naim DAC with XPS. The music is also presented with much more authority.
I went from a three box source (NDX > Naim DAC with XPS) to a two box source (NDX 2 with XPS) with an increase in fidelity and enjoyment, so it is two steps forward and zero steps back!
I am very, very happy with my system, but I am hoping Naim release a Naim DAC 2.