I noted what you wrote but how can you explain this:?
The lousy source I used was a CDX2.2 with a XPS 2 attached 
Nac 282 with Rotel RB 980 BX and volume at the Nac 282 at 7:45 o’ clock was already at 65 dB. With Naim you can cool and slowly turn up the volume until 8:45 or even 9 o’ clock and have 70 dB.
So my conclusion: The 2x 120 W from the Rotel are way more powerful.
But of course I can be terribly wrong here.
If a speaker is so demanding it cannot be driven by a 250, then it is a poorly designed speaker.
Nap 250 powerful enough that the fuse in my house blew. Switched off only Nap 250. Changed the loudspeaker. Switched on again the Nap 250 and bang… 6 Naim elements went off. Why ? What did I wrong? Why me?
Tell that to Apogee, MBL…designers 
The straight gain of the power amp is probably the difference here, and this is only loosely related to the power delivery. I can’t find a gain value online for the Rotel. The gain of Naim power amps is in the specs on the website
It happens if you have fast-triggering circuit breakers, like most people. The inrush current can make it trigger. The solution is getting the breaker changed to a slower one by an electrician, or try a few times and leave it on once it runs. (Of course leaving it on is not a solution when trying things)
and why do my very small B&W DM 100 i now sound much more aggressive in the heights, nearly unbearable and very lack of bass (good for my neighbors), isn’t it that the Nap 250 power tries to beat the crap out of it ? I suppose I need a floorstander for my living room and my neighbour rings at the door to tell me to durn down Sting. Mamma mia
That’s nothing to do with the power of the power amp;rather it’s all about the gain of the power amp.
do I find it in my Rotel paper manual (would only need 15 minutes to find it) ?
what I now like about Naim: I have connected 80 Watts B&W DM 100 i stand mounted speakers, and I thought I would only give a small volume tip and the huge Nap 250 power would be delivered. But no, it is perfectly continuous, nearly the same as if my 150 Watts floorstanders. Around 9 o’ clock I have 70 dB peaks. I really do not understand how that is possible.
I don’t think so, I looked in the PDF scan of the paper manual that Rotel have online. But it’s rather meaningless, anyway. The gain of Naim power amps is generally +29 dB (with occasional small deviations, I think the 500 has +28 or so). I.e. the signal comes out 29 dB louder. Another amp may have more or less, it’s a result of the design and by itself means nothing.
Hi
A lot of this comes down to marketing and the average person assuming a 2 x 30W amp will be worse than a competitor’s offering 2 x 100W.
Within the same manufacturer’s tiered product line at a given time that may hold some merit, but not necessarily.
There is actually far more to it than this when comparing differnt products/manufacturers.
Even very expensive Naim amps may look ‘underpowered’ compared to cheaper amps purporting higher W/channel.
One of the big considerations is what the amps can suddenly deliver during powerful transients when a lot more power may be needed very briefly rather than continuously and that unless I’m wrong is part of the Naim philosophy - steady output with the ability to really deliver those brief bursts when needed. Apologies for non-techie speak here, I’m sure Xanthe could put it more eloquently.
Assuming this is your Rotel, sorry for different pic sizes, but look at the difference in size of the transformers and largest capacitors:
Rotel
Olive NAP 250
If the 250 is new, it will take some time to settle down and it will improve.
Generally, Naim amps are not known for sounding overly pleasant, rather for having some urgency. And much depends on the synergy with the speakers.
The Rotel and the Naim are very different designs as well, Rotels generally have a huge damping factor, while Naim have a quite low one. I had Rotels before and thought they sounded rather stiff with some speakers, though others worked well with the strong damping factor, if their design by itself made their bass rather boomy.
Though usually this would mean less bass with the Rotel, so it does not explain your opposite experience with a lack of bass with the Naim. Are you sure that you have the speaker cables connected with correct phase on both ends of the cable for both speakers?
And what speaker cables are you using in the first place?
Hello. Let’s just not ask me about the difference. Could you tell us all what we should see as a difference. Which capacitors are bigger, which transformer is bigger? Thanks.
I’ve had 250 olives, 250-2, and now 250DR, and every speaker I’ve hooked up to these amps sounded great, ideal really.
The transformers are the big round things.
The ‘big’ capacitors (I assume, help @Xanthe), but not the only ones in either are above the toroidal transformer on the NAP 250, but 4 in a row in the middle of the Rotel.
I’m sure the Rotel is a very competent amp, just saying that output specifications in terms of Watts per channel simply don’t tell the whole story, and also consider if you think ‘power’ equates to quality then it all falls down if circuitry earlier in the chain cannot presevre the fidelity of the source no matter how good.
Hello. The Nap 250 is 10 years old and has around 150 listening hours (thanks to my former neighbours system was off) Yes all I connected in the last days just sounded wonderful. I use Naca 5 Naim cable.
Naim Nac 282/ Nap 250/ Hicap with B&W DM 580: Result perfect, lots of bass because speaker have a big volume
Naim Nac 282/ Nap 250/ Hicap with B&W DM 100 i : perfect, very little bass (on Linn Kan stands though) as little speaker volume
B&W DM 580: Rotel RB-980 with Sudgen HA-4 or Rotel RB-980 with Naim Nac 282: same result: power at 8o’clock at 75 dB already, and more bass, but I suppose that was before I found the best position for
the speakers, less toe in, much more distance inbetween
Sudgen A21 SE Signature with B&W DM 580 had not the same magic as the Naim system, and a little bit more bass.
Actually Diana Krall and Eyes wide shut soundtrack listened on Naim with the small B&W DM 100 i. Synergy works but limits when big orchestra plays, a little bright (I do not like the Hi-hat sound) for Bryan Adams “Waking up the neighbours” , piano sounds more natural (I played the piano for 4 years) than with the big floorstanders. Kurt Cress drum playing sounded thin, no wide soundstage. Way less soundstage than my favorites B&W DM 580 but more airy. Next could be CDM 9 NT, as I suppose for 27 m2 I need floorstanders, even if I prefer the airy standmounting speakers.
Ok, the basics don’t seem to be the problem then Maybe just speaker matching with the DM100, but as I don’t know them at all there’s nothing else for me to add
As a generalisation, no amp is “too strong” for any speaker (there are some exceptions, but not in mainstream hifi). What counts is how far you turn the knob! Many amps have very similar gain - tge degree of amplification - more powerful ones simply allow you to turn the volume control higher without overloading the amp.
More speakers are destroyed by amps that are insufficiently powerful, because when the amp is driven to clipping while trying to turn it as loud as is wanted. A clipping amp can quickly destroy speaker drivers.
I’m uploading a video to Youtube, sending link in 5 minutes
B&W DM 100 i with a high end Naim hifi system - YouTube
