Same cables.
Based on everything so far I still think itās an issue with those. So regardless of which amp you choose, consider exchanging those under warranty.
I tried different XLR, different RCA. So canāt be that. Itās very probably some nasty mains, because, in different moments in the day, the noises are very very tiny ( heard if my ear is touching the speaker) or more important ( heard at 5/10 cm).
Itās not the speakers, I just tried today another ones.
Not the amps.
The last thing is to try another pre.
I think you rolled tubes in the past. If you still have the old ones, try those.
Which one makes you want to stay and listen, not get tired after a while?
Already done
1 Like
I can listen longer with the Ear , because itās softer and gives nicer tones.
But the Naim involves me more and gives me more emotions.
On vocal tracks, the Ear is more magical.
I will listen once more on wensday, but normally I want to keep the Naim.
1 Like
Then I think the only thing left is to try another preamplifier. If that doesnāt exhibit it, perhaps the 912 should get a service?
1 Like
Sounds like you need to try another power amp to try to get the best of both. From Naim either a 500 or a pair of 350sā¦ (easy to spend someone elseās money!) did you ever try a 300? Now discontinued but of course available secondhand.
What other speaker did you try?
@frenchrooster, it seems you have already choosen which one to keep. However, remember that what you prefer now is not a guarantee that will be the same in the futureā¦ I know, it does not help! 
1 Like
I my memory serves me correctly, when you first tried the NC250 in place of your NAP250DR you thought it was a good improvement.
However the āvery tiny noisesā appeared and you decided to try the EAR 534 to see if they would disappear, but they didnāt.
With the fault not likely to be from either power amp, only there when you get very close to your loudspeakers, and only for moments during the day, to me, sticking with your first choice is the better one (if it gives the sound you want, of course). When the NC250 is fully run in, there is no doubt in my mind that you will want to listen longer.
1 Like
Can you try a different preamp, just to rule out the 912. There are at least 5 valves between the pre and phono stage and anyone of those could be noisy. I know when i had an 864 a couple of the valves started to go and created noise.
1 Like
How I like and hate this situationsā¦ think there will be no real winner.
You will miss the naim sound with the ear and the smooth magic when you decide for the naim.
You might also adopt to the ear sound or ā¦ 
Butā¦ the naim is much easier in rack placement.
Know this journey. Still have some āmiss SBL momentsā. And than I some electronic music with a lot ābeatā into nd555ā¦ and energy is pushing as never before ā¦
In you situation I would also consider some upgrade path - even if not todayā¦
This would be the nc250ā¦
1 Like
@drago HiFi is rarely about absolutes. Most often choices involve trade-offs. At some point in time, you will need to decide. If for no other reason then for serenity.
3 Likes
Itās what I will try next. Itās the last possibility. However the pre was serviced 2 years ago. The tubes were replaced to see if it was that. But no.
For now I have no budget for a different amp or speakers. I am not disappointed by my system. Perfection doesnāt exist. To have both what the Ear and Naim give, I would have to invest much much more. And buy another houseā¦.
3 Likes
Exactly, itās always a compromise. Or you need to have a 300 k system and a room to go with.
1 Like
Wise words. And sometimes you need to have the courage to try something new. Working on that.
@frenchrooster
Keep the 250 - foot tapping should be the factor (to my experience). Even if a bit more edgy, let your feet decide 
2 Likes
Even with 300k there are compromises
1 Like
Full Statements, or VAC, Ypsilon phono, Top Sonus Faber or Wilson Benesh, ND555/ 2X 555 dr, full Chord Music, HRS rack, SAT turntable and arm, Lyra Etna, and a 50 m2 room with a wonderful view.
3 Likes