I have Naim Nac 62 with Nap 140 with a (don’t all hit me at once) a non-Naim power supply and and have now bought a Naim Nait 5i-2 . The former sounds good and the new integrated amp sounds a bit thinner to my ears with a tad less bass.
I am using budget speakers, Dali Spector 2’s , which sound really good in my small snug. I used to have Castle Durham’s for a few decades, but the Dali’s are very spacious with a good bass in that room, which I can adjust by moving to/from rear wall. I have thought about N Sats and AE1’s, but frankly my speakers work well in the space the they are in.
I’ve edited your post. Please note forum rules with regard to discussion of unauthorised modifications, which includes 3rd party power supplies, SNAICs, etc…
A NAC62 and NAP140 on top form is still a formidable combination, which, if still made new, would cost many times that of a NAIT 5i. So if you prefer the former, that’s not so surprising. Of course, as ever, much will spend on the source. How are you fronting each amp?
Apologies for my digressions. I am running a Regar Planar 3 turntable (where I cannot get any volume worth mentioning on the 5i using the AV input (as advised by Naim on the phone before I bought the amp) a tape deck, a tuner and CD player.
You must use a phono stage, look at the rega fono mm. The nait 5 doesn’t have a built in phono stage. That’s another £200 unless you find a 2nd hand one.
If I were you, I would;
Get a proper hicap
Get the 62/140 serviced, ask Darran at Class A.