Okay, I assumed that Naim preamplifiers aren’t just added in for the fun of collecting boxes. 
For me, though, that’s a no-go. I really wanted a one-box solution, but it didn’t work out for me, not even with Naim.
I can definitely imagine an NC 250, but a pair of 350s is already in the price range of a compact car (a Romanian, of course ).
…and the occasional transformer hum in the quiet room is back again. 
I have found that mine is at its worst when any of the major appliances (Washing Machine, Dishwasher, Tumble Dryer) are running. It is obviously something to do with the heating elements in them. 
Ovens probably do it too, but I’m never in the cabin when I’m cooking so can’t be certain. Also, hardly use them anymore now that we have an airfryer😊
Getting to a system, especially of this price range, was a journey for me. Started with Atom, then Nova and then slowly worked to a NC 200, and then finally NC 300 system. When the firmware gate hit, I was looking for a 333 replacement. My dealer allowed me to audition both Linn KDSM and Selekt Organik streamers. With the new options, the opportunity was to replace 333/332/300 and move to a three-box system with just Linn frontend and 350 monos.
Linn streamers were impressive. They easily beat 333 in streaming and DAC performance, so it was an easy choice to trade in the 333. The one thing I wasn’t impressed was running Linn direct into 350s. Both Klimax and Selekt were not fitting the 350s. There was so much missing without the 332/300. Naim NAC is a very important part of Naim system.
In the end, given the price it wasn’t logical to buy a Klimax and run it with an external preamp. So I settled on just as good performance of Selekt dual Organik, but with 332/300/350. I’m very pleased now and enjoying the music. 
Selekt DSM Edition dual Organik, 332/300/350, Borresen C1 and various other accessories.
If you need help adding your gear to your profile… click on your avatar top right>hit the little icon below that looks like a person>
hit preferences> hit profile>hit expand then scroll down and there is a system option where you can list your gear.
That is a very nice system! I have the dual Organik Selekt running directly into 350s and I am very happy. To be fair, I have never heard it with a 332 in the chain. I am sure I would quickly realise this delivers an improved sound, but I am happy living in ignorant bliss with my current set-up, which sounds mighty fine and avoids yet another expensive power cable and interconnect 
How do you find the Borresen C1? Do you mind me asking what speakers you had previously and how they compare?
I’ve learnt to just live with this now and accept it. Mine is noticeable when no music is playing but it is really not that bad and definitely nowhere near as bad the SuperCap DR I used to have!!!
I must admit that is a downside of moving back to large transformer Naim amps in my lounge system. My NAIT 50 is as quiet as a mouse, but my 350s tell me exactly what the mains is doing…
No issues with anything in the house, but just down to external factors which at times can make the amps presence in the lounge a bit more noticeable.
Thank you.
I’d be very happy with your system as well. It’s not like you have a bad one or an average one either.
Love the C1s. They are my favourite piece of the system. They are not perfect, but for my 20sqm living room, they fit well.
Before them I guess I had the usual cliché, Spendor D7.2. There’s no comparison, it was a side move to a different sound profile completely for me.
Thanks, I’m not complaining and after moving to Ansuz wiring throughout it has really come alive 
Good to hear about your experiences with the C1s, @SRO has the 01s and is equally as happy with them. Both the C1s and 01s are certainly great looking speakers and I am sure sound fantastic.
Have you tried an iFI DC Blocker. They worked on my two 250s.
DG…
Ah that old Naim transformer hum!
I guess I’ve been quite lucky. Of all the Naim boxes I’ve had over the years, the only hummer I’ve really suffered from was an XPS, but that was loud enough for my long-suffering wife to complain about it. It eventually went and with current Selekt/active ATCs transformer hum is a thing of the past … I hope.
Roger
Over the years, I’ve tried various DC offset compensators. They all worked, but they all also worsened the sound. Some more, some less. The iFi DC-Blockers had the least negative impact, but even they reduced dynamics.
I’ve not, DG. I remember your thread when you had your 250s. I see Futureshop sell them so that’s a no risk way of trialling them.
Good reminder, thanks
They worked for me and even better had no impact on the SQ on my system.
As you said, worth a punt.
DG…
Time for that trial of active PMCs methinks.
You could be right, Nigel. Active PMCs are certainly of interest here.
Years ago, I’d sometimes hear a hum from my four 135s, two Hi-Caps, and a NAPS (? - the NAT01’s power supply). I didn’t think much of it back then, and it happened very rarely. This tells me two things: first, I’m getting older 
, and second, the mains power quality 25 years ago was a good deal better than it is now…
Glad you are enjoying the 250. I have heard Linn amps for a/b comparisons between different Linn KDSM versions (old style KDSM, Select and NG) but I never got on with the sound/presentation itself. I much pref to run my KDSM NG into Naim pre/power. Lovely combination. Enjoy.