From my experience living with the SN2 for many years, and now not…the SN2 makes wonderful music but the 252 makes way more wonderful music. I’m sure it doesn’t do ALL that the NDX2 can provide.
The reason I mention this Bart,fellow member here (Spurrier Sucks) is thinking about switching from a 272/XPSDR/250DR to an NDX2/XPSDR/SN2,and I am trying to convince him that it is a sideways move.I have owned the combo he has now,and once owned the SN2/High cap DR,so I am familiar with both combo’s.
Sideways I can deal with but I don’t want to go backwards. I like the idea of having my source separate unlike with my current 272 and former Uniti 2.
It’s a tricky one. Clearly the NDX2 is quite a bit more capable streamer than the 272 … and ultimately more accomplished performance due to the new Naim learning on digital and noise management and low EM emissions… not to mention next gen streaming capability offering robust Tidal replay, Airplay, Chromecast, local UPnP media server, and Roon… However the 250DR is an accomplished power amp… and I suspect the preamps in both are pretty equal. It’s a shame SS can’t keep their 250DR and some how stretch to a 282 HiCapDR or higher…
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Getting back to the 552 I’m demoing, and perhaps @Darkebear can help again.
Yesterday (day 8) heralded a distinct ‘improvement’ in SQ, but in the afternoon I listened to Pink Floyd DSOTM. There were some very intense HF guitar notes intermittently which were almost painful. The volume control has been around 8 o’clock and in general 20-30 mins lower than the 252 which was lower than the 282. Later in the day after the Brexit votes the sound of tv and music was more mellow and not right. This morning some ear discomfort.
So the question is whether the 552 burn-in process can include abnormally intense HF response (obviously requires the music to contain sharpe HF notes in the first place).
Alternatively is this normal for DSOTM and the 252 was not good enough?
Finally a request for descriptions of the sound produced by the 552 at its worse during the burn in cycling. I do believe that in the last 4 days there have been variations in SQ, but yesterday may have been the biggest.
Feedback much appreciated. I think I need to let my ears recover a bit.
Phil
You can get some HF ‘zing’ when some items like 552 are not positioned on Fraim glass shelf correctly - usually they are placed too far into the middle of the glass and need to be moved closer to the front of the glass shelf. I’m here assuming you have it on Fraim.
As the resolution improves then you hear set-up issues. The items with internal suspended sub-chassis have solid hard external feel on the box to prevent coupled-oscillations with the external box mass and squishy-feel normally used and the internal sub-chassis decoupling self-resonant frequency.
The issue is that the Fraim suspends the glass on 3 feet and the rear of the shelf can flex and ‘zing’ against the box which with the rubber feet is prevented but with 552 is not - you need to carefully re-position and it goes; near the front of Fraim about 1mm from glass front - also check the glass is level with the wood of the fraim and symmetrical each side with the balls. The latter impact SQ but the glass position causes the ring.
The 552 and other items higher-up the range resolve more power into the harmonic structure of music and the rule ‘if it can ring it will’ applies with everything. Before that was not a problem but the extra clarity of resolution just means you need to chase-down the installation.
But it may be something else! Just make sure the above is not it as it is easy to fix and two other Forum friends had the same problem as me when I discovered it. I also had it with my then CD555 after I used DR supplies as it got brighter until I re-positioned on the glass.
Some boxes with the normal rubber feet can sound a bit better not at the glass front, but in general I have mine nearly aligned with the glass front.
Until you experience it you won’t believe it is important.
DB.
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Phil, I have never had the HF shrill signature you describe with my 552, even during the warm up process.
It could be a number of things and DB refers to the sensitivity of set up relating to positioning the 552 on the Fraim glass shelf. This reminds me that you have HiFi Racks with glass cups and balls added. The 552 could now, having really warmed up, be exposing the shortcomings of the HiFi Racks support compared to a proper full fat Fraim.
In addition it would be wrong to criticise the 552 on one album (and one master version of that album) alone. I have a CD copy of DSOTM and it is terrible. Not sure what version yours is, but try some other albums that sounded good previously with the 552.
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I have four CD-rip versions and the first master is rather raw but is most honest to me. As my system improved this went from murky to quite good as the low-level detail was properly resolved and separated from the noise.
The next remaster has better HiFi but loses something…and so-on. I think my musical-memory is keyed to the Vinyl of this album and all its idiosyncrasies need to be rendered as they were then released for me to immerse myself with it.
Any remaster can genuinely be better - sometimes they are but not that often - but even then a different compromise is made and I usually find a form of ‘noise-coring’ has bee done to remove both low-level noise - and unfortunately musical info I liked. A cleaner HiFi version with the missing part - all personal to which you prefer.
DB.
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For what its worth, I too noted some “zing” initially with my then new 552 which gradually disappeared now at the roughly 6 month mark. Otherwise nothing else changed.
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Hi Nigel, I deal with DSOTM first. Mine bought at Oxfam for £3.99 is the Harvest CDP 7 46001 2 (UK, 1984). I think it is the first UK CD version.
From the SQ point of view it sounded very very exciting, albeit with zing to some notes. I have 1973 vinyl bought for £6 which has some surface noise at the beginning, but I haven’t played it with the 552 yet. I stream with Innuos Zenith Mk 2 into nDAC + 555DR.
I reply to the other posts and point separately.
Thanks for your input.
Phil
Needs a different thread but I have heard the 272/250DR at my dealer’s (I used it to audition some speakers) and it’s quite capable. I’ve not heard an NDX2, but “sideways” would be my guess about that system change as well. Me personally I’d not make this change unless I got the chance to really listen to it in my home and liked it (which could well happen). But “on paper” I’d not do it, as big a fan of the SN2 as I am.
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Hi Bart probably a good idea. Maybe ask @Richard.Dane if he can help or posters could remove the post.ps to a new thread.
Phil
Hi DB, well have not read much about the tweaking of the glass, cups and ball bearings, which apart from the glass which came from a local merchant are Naim parts.
I probably had noticed you mentioning before to put the box lined up with the front of the glass and I do that. What surprised me from your post was the importance of box position on glass and that the sprung suspension boxes have ‘hard’ feet.
As @NigelB points out I do use HiFi Racks and I admit to being reassured by @Clive when he visited on Monday. This kind of purchase does need justification.
Well, checking the 552 after your post I did find it 4-5mm back from the front and the cups in an odd position. Here I suffer the same as Fraim Lite owner who add glass - there is no seat for the cup to ensure accurate positioning on the wooden base. Might the boxes move much more easily over the glass or the glass on the ball bearing?
I also have to admit that I did not think the position of the cups below the glass would make much difference! I got drawn to putting the cups under the box feet approximately for reasons of simplicity / repeatability. I know Fraim is provided with a paper template to position the exorbitantly priced plastic safety retaining rings on the glass. These also do not position under the box being forward and outside the front feet. HH (Nigel) once expressed the view that the retaining rings were a waste of time! I just use them on two top shelves.
I would very much appreciate views on the best place for the ball bearings relative to the box. I could stick the cups to the wood once I work out the best position.
I guess if the SQ is noticeably affected this might explain some long term SQ variability issues I have had.
Many thanks to everyone.
Phil
The 552 is wider bandwidth preamp, which is why it works so well. However this can expose issues with speaker placement and room reflections… and this quite be quite telling.
For example I felt I needed to reposition my speakers because of the increased low end bass when I got my 552.
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I have done the Master Set speaker position check (there is a current thread) with Jennifer Warnes Ballad of the Runaway Horse. I concluded the bass, her voice and the soundstage were good. The zing is a pain.
Phil
I only have Fraim (now described as full-fraim) and no experience of the lite version as Naim had not invented it when I purchsed my set - but I had experimented with alternative positions of the three mounting points from Naim’s suggested ones.
Perhaps not surprisingly I found the glass is highly responsive to where you place the three points on the ball bearings, as these set the null-points for the vibration modes the glass has available and you can tune these to have the set which sound best. Also Naim seem to cunningly tuned their box feet positions, internal sub-chassis resonance and the glass to all sound best where they suggest.
Also the type and thickness of glass matters to the end-result and I only managed once to find a bit of glass I prefer on one open shelf under my source (ND555 and previously CD555) over what Naim offer. Naim’s glass expects a box sitting on it with feet where they are expected to damp the glass at four points and an open shelf I found works a bit better being slightly heavier (but not too much). In fact this is only because my source fraim stack contains two empty shelves which ‘talk’ to each other unless one has a slightly different self-resonance set of modes.
There is a long reason why I did all this - but it works and I’m happy is where I reached.
In your case I’m suggesting it is worth getting any glass shelving under the 552 in the right place either by using a full-fraim shelf - IMO the best method - or trial and error with what you have to find the sweet-spot and then record that position and ensure you can put it back there if it gets moved.
DB.
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Not entirely true, speaking for myself, as the one who used to own a NAC 252/NAP 500, and 2 Fraim racks.
@Filipe when I brought up the subject of the positioning of the cups and balls you said that you had positioned the retaining rings using the paper template (which, given that you don’t gave Fraim, is the best approach). I had assumed that you had then used the shelf with the retaining rings to position the cups for the shelves without retaining rings. This would still not position the rear cup and ball in the right place, of course, but I will measure these locations from my Fraim and let you know if you like. In my case the glass shelves are flush with the front of the wooden shelf and the 552 fascia is set back by about 3/8” so that the volume and balance controls protrude by about 1/16” or so beyond the front of the glass. I’m not suggesting that this is optimised in anyway, but I doubt you’d find consistency among dealer set-ups either.
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Clive, Thanks for your measurements. What surprised me was that unless I was careless the 552 had moved. I will have to be more attentive and experiment more!
DB thanks for your input.
Dave, given that to mirror the three wooden racks would cost as much as the 552 upgrade I’m not so sure. I have the benefit of a solid floor slab rather that wood which can resonate more.
My plan is to run the 252 in a second bedroom system (lowly ancient unserviced NAP 90 into Spendour A6Rs) so it gets warmed up. Then get the dealer to come and listen to the best the 552 can do and do a ‘hot swap’. My feeling is the 252 should be good enough if it consistently is at it best. I think I am very fussy. Then I may get my dealer to loan me Fraim for the brains stack to see what it can do.
Phil
I’d suggest you don’t say anything about positioning etc. and just let the dealer set up the NAC552 to optimise performance. It would be interesting to see how he does it without influence.