This can produce very subtle changes in my experience. But hey, just trying to help, and I have never regretted having the 400mm to get in and check and improve the cabling behind. In the end I managed to get the 2 SL IC and DIN to XLR hanging nicely and the Powerlines also. Wool carpets may have helped as opposed to wooden floor boards.
Phil
When I first installed my 500 in place of a 250 I had a similar loss of engagement. I put it down to the 500 needing a service and as Iād bought it with a view to getting it DRed arranged to send it off as soon as I could. Replacing the head unit with the 250 brought the engagement back again.
When the 500 returned and was reinstalled it was still un engaging but now I couldnāt blame its age. Moving the 500 power supply up in the right stack got the Burndys mostly off the floor and improved things a bit but not enough. Then I moved the 552 higher in the left rack so it was above the level of the highest ps, that did the trick and I could start enjoying my system again.
Very strange. Iām afraid i canāt offer any clue.
Do you still have the 300DR ? Are you able to swap it back to confirm the issue is with 500 vs. 300 ? and that itās not something else that has changed (in electrical network or whatever else) ?
I have the same system as you except that I have Sopra 2 and iām still with a 300DR.
I was wondering what would be my next move when the time comes : 500DR or Scala Evo ?
But in your case I doubt that this is revealing a speaker weakness, knowing what the Sopra2 are capable of, the Sopra3 must be even better and with still more potential to express as the rest of the system upscales.
I preferred the 300 to the 500 and found the 500 a rather uninvolving listen. Iāve not directly compared the DR versions, though owned the 300DR for a few years and heard the 500DR on occasion. Maybe you just prefer the 300 presentation. Itās a damn good amp. More isnāt always more in these things.
It to me seems that the the higher you go with Naim the less engagement you get. I had same experience going from 250DR to 300DR but decided to stay with 300DR however I often wonder how I would feel about getting 250DR into the current setup. Same going from SN2 to SN3 where SN3 is more related to 300DR than foot tapping 250DR/SN2. It seems like the idea of better audio within Naim is more laidback, neutral/HIFI and for many less engaging?
I wouldnāt disagree with much of that, other than the last two words of your post. I would also replace the word āneutralā with ānaturalā.
I quote from my posting on another thread where I talk about an uplift in SQ from a room change:
'It is weird in that music is presented so naturally, no pyrotechnics, no crash-bang, no exaggerations, no OTT in yer face āave some er that! In a way, rather unimpressive, but all the more impressive for it, and deeply involving, if that makes any sense.
I am listening to Cara Dillonās album Wanderer. Gosh it is wonderful. I just wasnāt getting the delicacy of her vocals and acoustic instruments in my small listening room. Good hints of this before, but not drawing me in so much as listening now in the larger room.ā
So if the OP is feeling a lack of engagement with the 500DR than I would suggest something is wrong.
Not something Iāve ever experienced! 
Great summary. The more natural no nonsense sound can take some time to adjust to if you come from a ācrash-bang pyro sound signatureā and the more we pay the more nervous we tend to get with sometimes too high expectations and then the new equipment can start to mess with your brain. I love my 300DR and it grows on me week after week which is something else than the more immediate 250DR/SN2. However it was more of a struggle in the beginning with the same hesitations as the OP of this thread. Iāve learned that one of the best tips in these situations can be to just let go of the SOUND, cable dressing and technical matters and start listen to the MUSIC. Then it very often starts to fall in place.
I agree with all of that.
I canāt agree with this.
The 500 needs to be so much better than a 300 because it cost so much more, and indeed to my ears, it sure is better.
something is wrong, and needs to be remedied.
In the Naim upgrade, thereās no "ifās and ābutsā, every level is better than the lower one.
Unless something else is wrong (installation, cable dressing, mains, RFI or something else)
Thanks again for all the thoughtful insights. The answer is probably multifaceted.
@anon4489532 makes sense in that it may simply be that I prefer the presentation of the 300 over the 500. Various tweaks that were recommended and especially experimenting with speaker and listening position may be worthwhile.
There are aspects of the 500 that are clearly better. Expectations Iām sure,play a role as well.
Sometimes something just doesnāt work in a particular room, system, pair of ears. This is why it is vitally important to audition at home first.
The 500 is a remarkably subtle beast in how it communicates, almost a āless is moreā proposition. The grip, transparency and sheer believability it brings, particularly to a 552 is no surprise for the asking price, yet remarkable when you compare it to a 300, itself a superb amp (and IMO the best value for money power amp Naim currently makes).
If it doesnāt work for you, then it doesnāt work. But it is more likely (not certain but more likely) that something is wrong. The speakers should just get out of the way and let the music sing. The 500 and 500DR can take months to fully run in. I assume you leave it switched on 24/7? Having said that, it ought to sound fantastic out of the box.
I had a similar problem with my 552, which we first used into a 300, later adding the 500. It just didnāt have the magic of the audition unit. I gave it a good 12 months to settle in. It sounded wonderful but it just didnāt engage and communicate like I thought it should. Naim took it back and Roy gave it the once over. It was rebuilt and one component (that I know of, it may have been more) was replaced. When it came home again the magic appeared instantly.
You are on safe ground with Naim. Unless the 500 just doesnāt somehow match your room/system for some reason, they will take your disappointment seriously and try to help you, be it the supplying dealer or the factory.
I really hate to hear that you are not happy with the move to the 500. I went from the 300 to 500 and found it to be a big difference. But I must add that at the same time I went from the 252 to the 552, so not the same as your journey. That may well prove have good the 552 is. Also instead of Sopra 3s I had the Maestro Utopiaās which I suppose were too much for the 300.
Hi Phil,
Out of curiosity how is you plug-in order into your G3? Best Peter
I think that one thing that can happen is that a lesser system will tend to reproduce all, or most, frequencies below a certain region as a somewhat higher frequency range. So, for instance, all the music energy below, say, 60Hz is reproduced at around 60 to 100 Hz. This can sound quite impressive - being louder relative to the higher frequencies. And our ear/brain system can interpret some of this as being at lower frequencies (which is why a kettle drum can be identified as a kettle drum even by a 2.5" speaker on a transistor radio). With a better system, some of this low-frequency volume decreases (or seems to) because it is spread over a wider range of lower frequencies. This can sound less āimpressiveā, but it is more accurate i.e. more like it was intended to sound.
Speakers that I had years ago were very good (for the time) and reproduced music well. However, at the lower frequencies it couldnāt reproduce the true notes, but tended to lump them all together at some - fairly low- frequency range. Changing to other speakers that could actually go lower resulted in what appeared to be less oomph in the lower registers - but actually what was happening was that there was more information in the very low frequencies.
Itās a little like photography. You can increase the contrast in a photograph, and it will look much sharper than the low-contrast version. But in fact, there is less information there.
Hi @jsaudio
I had the 300DR and now 500DR.
I bought both amps new and compared them, side by side, in my own system.
For me, the 500DR is immensely above the 300DR.
It brings a lot more details, has a much lower noise floor.
It performs admirably well with complex music like classical.
When it comes to big orchestras the 500DR has a massively better ability to picture the orchestra, whereas the 300DR is blurrier.
But I well understand you may prefer the 300DR. Both amps are brilliant.
For me, the 500DR made THE difference.
Acoustic music is something delicate. If something is not right you notice it immediately. For me the 300DR was very good, but the 500DR sounded closer to the real thing.
Some think the 500DR is just about power. Well itās not. Whatever speakers it drives, smaller or bigger ones, they all benefit from it.
It brought complex music like piano, voices, cellos, etc. to another level 
That said, if it is the 300DR that brings a smile to your face, than the better amp is the 300DR. No discussion. And lucky you, the 300DR is a lot cheaper! 
NOTA :
Here are my first impressions when I swapped the 300DR with the 500DR
Sometime I will move the G3 away from the dent it has made in the carpet. Being very cautious these days - if it aināt broke ā¦
Phil
Streaks are light effects caused by fingerprints on iPad Air 2 lens. It certainly aināt broke.
That did make me smile 
( welcome to the club of equally afflicted).
Very interesting that my plug in order is similar to yours, as Iāve spent āsome timeā mocking about with various permeations:
ATB Peter
Iām resisting catching that affliction, which is why I started with sometime! If I do you are the infection vector.
Phil
Just as a suggestion do you have any isolation feet on your Sopraās, I have the Sopra No.3ās and have fitted Isoaccoustics GAIA Iās. To my ears they certainly make a difference to the sound, more focus and maybe with the 500 amp it may make the system sound better. I only have the NAP 300 but that sounds pretty darned good to my ears with the Sopraās and the GAIAās fitted.
