It should be quite a step up.
I’ve tried A-B testing (HiLine vs Super-Lumina). Super Lumina, to my ears, is an instant improvement. To a point, that in my 2nd Naim system, I actually use a SuperLumina ‘full loom’ and Naim PowerLines only.
You can also try Chord or TelluriumQ, but… there is always that but… I’ve tried them all and at the end of the day I always come back to Naim’s own cables.
Yes! 
Yes for me too !
ATB, J
Super Lumina is a good choice, the most important interconnect is usually between the dac and pre/amp. The choice may be price influenced though as it is always possible to get better used cable vs new.
Superlumina is very good and with 1,5m length it is even better to dress. Between DAC and pre the difference is big and clearly noticeable
Are you saying 1.5m sound better than 1m?
No 
But in my case I could use it as nd555 and 552 have some distance
Exactly my experience except for speaker cable.
In fact, I would go as far as to say that if you find that another company’s interconnect sounds better than Naim’s, there is something wrong, somewhere, in the system. I have found this to be the case in my Linn system (with Linn interconnects).
Don’t agree completely. It’s not that difficult to go beyond Super Lumina, not even mentioning Linn)
My point is that the perceived quality of an interconnect is within the context of the elecrtonics, which were, in the case of Naim for example, develoed and voiced using Naim’s interconnects. So, my question would be this: would you replace the capacitor or transformer in a Naim box with a different one? Different interconnects will bring different sounds, I agree. But better? How many people here say that they return to Naim originals…quite a few. Why…probably because superficial differences in sound become fatiguing. My opinion only.
Some have never changed from the Naim ‘originals’… 
My set up is -
Naim DIN5 to DIN5 / Black SNAIC(s) / Naim DIN4 to XLR / Naim NAC A5
Keeping It Simple.
I would totally agree for the Power lines, which definitely have synergy with Naim boxes. For interconnects I always observed kind of linear dependence of price/performance. For example I agree that Super Lumina is a somewhat better cable than Tellurium Black Diamond but at 2x price in retail. And when you go at 2,5k there’re very, very serious options in a used market.
Der GT1960, very interested that you chose to buy a new power supply for your existing NDX2, and not go for the new Naim NSS 333 streamer for similar cost. I’m planning to upgrade my NDX/XPS and was thinking of stretching to the NSS 333 rather than an NDX2. I did audition the NSS333 and it was terrific.
Look forward to your reply.
V best,
ADRIAN
As long as you have given a proper listen to what you are rejecting, it’s hard to argue. In my case, there didn’t seem to be much wrong with the system to my ears or those of 2 musicians or 2 chaps from the excellent local dealers. Otoh, Morganas beat standard Naim in much the same way that a Hydra beat 4 separate standard mains cables from Naim or the dedicated mains supply beat the switched sockets from my domestic ring.
I am a little curious about those who stick to standard Naim cables because Naim clearly knows best and voiced cables and boxes together - but then reject Superlumina (because after all what does Naim know?) or the Chord cables that were very much designed with an expectation that many would be using them with Naim.
If it sounds right to you, however, that’s the important bit.
In my 2 systems the SL interconnect was too much of a good thing - better in all hifi aspects than HL, but ultimately a fatiguing listen. Was a pleasant relief to return to HL.
Imteresting point…I would make a distinction though: Interconnects are inter-Naim, power cords are not.
I think that fatigue over time is probably the best arbiter.
All my Naim units pre-date Super Lumina, some by decades.
I do own & have used Chord cables - they are my ‘go to’ where a Naim cable may not exist.
I also ended at the naim cables after testing…