Vibration & CDs

Do you mean the shelf itself vibrates?
Is it the same CDs and does it do it every time on these?
Have you played these CDs in an other player(at you dealer for instance)?
From your comments though I assume your dealer can't replicate it.
Again if the whole machine vibrates it points to a CDP problem.
Out of interest what CDP?
Stand by for lots of it should be on £4000 worth of magicframe or such like.

Howard

Hi Howard.

Before I continue, I'd like to point out that 99% of cds seem to be fine. There are maybe four or five cds that I own which are problematic, and there's nothing I could see that's unusual about them (I looked for any bumps or obvious warps, and also for unusually 'biased' labels).

On one cd in particular, the shelf does indeed vibrate. In fact, it makes a bit of a racket. As I play past the first few songs, it tends to diminish, if that's any clue.

The dealer has tried to reproduce it and managed - had a replacement transport ordered and fitted and claimed it was all ok. However, all was not ok and I then looked to some incompatibility with the cdp and rack (QS Ref) but found that the rack is only 'echoing' the vibration that's in the cd player on those few cds.

It's a Resolution Audio Opus 21, and I otherwise think it's one of the finest cd players I've heard (second only to the CDS3/XPS2 as it happens).

I'm just wondering if it's some design flaw in the player which causes certain cds to become slightly unstable, rather than a fault in my machine in particular. This would explain the fact that the new transport also has this problem.

I wonder if there's any mileage in seeking a refund - especially since the dealer has been well aware of this problem almost since day 1. Anyone have any experience of such things? It's still under warranty, but my concern is that though the dealer continues to be prepared to look at the player, there will come a time when it is out of warranty and I'm not so sure they'll even want to know then.

By the way, this is a Naim dealer and I'd hope they'd see their customer right over this. Especially when said customer has been a good customer over the last four years or so.

John

I have encountered the same problem. Also I am really pleased with the sound of my cd player so very reluctant to change. This is the manufacturer's reply and might be useful for you. I am reluctant to name the manufacturer since I find that they have been very good in addressing the problem and they are working on a solution - I would want to avoid making bad publicity for them for what is a relatively small problem.

"The cause of the problem is that these discs are made with the
central hole off-center (not concentric). This causes the disc to
"wobble" as it is played. Since a CD is read from the inner diameter
to the outer diameter with a constant linear velocity, the rotational
speed is higher at the beginning of the disc, and there is enough
vibration from the wobbling disc to cause the transports used to rattle as the first few tracks are played.

We have measured several discs that cause this problem, and while the
"runout" is far greater than most discs, it is still within the
specification allowed by the Redbook CD standard. So the discs
themselves are not technically "defective".

It is interesting to note that, so far, all of the CDs we have
examined that are manufactured off center were made in Germany.
Apparently, one or more of the CD pressing plants in Germany is
manufacturing defective discs. This explains why we have had almost
no complaints from other parts of the world.

While this noise causes no damage to the disc or the player, we agree
that this issue should be addressed. We do not have a final solution
at this time, but are continuing to work with the manufacturer of the
drive on this issue. Please check back with us in April or so to
monitor our progress towards a solution.

In the meantime, there are a few approaches that you can try:

1) Try to find another copy of the disc that was manufactured at a
different pressing plant.

2) Copy the offending disc onto a CD-R. This should solve the
problem, as we have never seen a CD-R with the off-center hole.

3) There is a machine that will "true up" these defective CDs. You
can see information on this machine at:

http://www.audiodesksysteme.de/de/index1.php

One benefit of using this machine is that, from all reports, the
sound quality is improved after the CD is "trued up". Unfortunately,
the machine is too expensive ($500) to recommend to the normal
consumer.

Please accept our apologies for the inconvenience you are
experiencing and know that we are working to find a permanent
solution."

John

the first thing, I would have thought would be to ensure the problem CD's play OK in an alternative machine. If they do than at least you know it's a Player and not CD problem.

The transport rotation speed is greatest for the first few tracks so anything of this type is likely to be seen then. I don't know what clamping arrangement is used in this player but it could be that these particular CD's have a slightly too big hole, are slightly thinner, slightly unbalanced etc and your CD player is particularly succeptable to this. it's a bit like the Naim 'problem' with some thin CD's. The worrying thing to me would be that the vibration may shorten the transport life, however you auditioned extensively and if it is only 1% of CD's I wouldn't be too concerned.

However if you are hankering after a CDS3 (and who wouldn't ) then it might be an oportunity to change, but as you say the CDS3 is 3 times the price of your player so it's not a cheap option.


Sorry - posted the same time as JamesH. His reply I would have thought is the most likely cause.

James, thanks for that excellent reply. That makes a lot of sense, and has got me to wondering whether my cd player is actually making a stab at playing a disc that perhaps other players might have rejected.

That said, this disc plays fine in our car, so perhaps it is something peculiar about how the Opus reacts to imperfect cds. I'm actually both relieved and disheartened at the same time (if it's possible to be so) as (a) I now know what is likely the reason why it's happening, but (b) my dealer would be less likely to entertain any notions of refunds or transport updates if he is aware of the above.

Hmmmm...

I do quite hanker after a cds3 - I feel the Opus betters a CDS2/XPS but the balance of power swings back (and how) to Naim in the case of the CDS3. Now that I'm Naim'ed in the amp dept., I am quite amenable to the idea of the CDS3, but as you say the price of admission is steep. Not quite the three times you mention - £2900ish versus £7500 I believe - but still one heck of a jump even supposing the dealer gave me my money back.

Did wonder about swapping Opus for XPS2 and buying an older CDX as a stand-in whilst I wait for my six numbers to come up...

Thanks, but still interested to find out whether other members have had any experiences like this in the past...

John

James, quick question: send via private if you prefer, but which cd player do you use? The Opus 21 is a tray-loader, non-clamped/pucked, and is otherwise a complete bargain as high end cd players go IMHO. However, if I have to CDR the odd cd then so be it - it's certainly cheaper than suffering depreciation and the extra cost of moving to a CDS3...

John

John,

If you considering a Naim CD player maybe you should try a new XPS2, Super burndy and a used CDS2 head unit. Should give give a performance is that musch better than CDS2/XPS1

Hi Dev,

quote:

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If you considering a Naim CD player

---

I'll stop you there, Dev - thanks for the tip, but I'm really not planning a change of cd player. Very happy with the Opus, despite this vibes issue. Having read James's excellent reply above, I've got a bit more peace of mind, though I will email the manufacturer anyway (as perhaps they have a fix in the pipeline).

If I did ever go to Naim for a cdp I think it'd be CDS3/XPS2 by way of CDX1/XPS2 (to split the painful cost!). However, hopefully that won't be necessary. In many ways my Opus is as satisfying as my LP12, which I think is a great achievement in a cd player at that price, and movign back to the standard Naim i/c has made things sound even more 'analogue'.

John

John.

Get these thoughts out of your head . I thought you said a few days ago you were going to stop posting and just listen to your system that you were now very happy with. Since then your talked about changing the 250 for 135's and now CDS3 enters your thoughts, put a stop to this now or you know the inevitable conclusion.

quote:

---

listen to your system that you were now very happy with

---

In my defence, I did decide not to bother with 135s - mainly due to the fact that my system is sounding so good right now and I'd need to find more cash and another shelf on the rack.

I really am delighted with my system - vibrating cd player aside - and the only thing I plan to add is a prefix. The CDS3 idea was borne only of my realisation that that player would be where I'd have to go to to improve on my current cd player - again, vibes aside.

After all, £5k would be a lot of money to spend to play a few cds - when a couple of quid allows me to cdr them instead.

I guess I was worrying about nothing - perhaps. I mean, out of six or seven hundred cds, this vibration only happens on a handful of discs at most. I s'pose if I CDR those discs then - problem solved!

John

Sounds like a good idea CDR them an get back to listening.
Anything to be gained in listing the offending CDs to warn any body contemplating their purchase or see if any one else has a problem with the same discs.
Apart from NAIM upgrading the PIC codes was there anything they could do about the manufactures of Non Red Book disks?

Howard

The Opus 21 uses a CD ROM transport - correct?

If so, it's probably spinning up to way higher than the normal start-of-disc 500 rpm, and thus ANY deficiency in the disc will cause it to make a racket. The CD drive on this PC at work sometimes makes one hell of a racket.

That might not be the problem though. However I've never found a CDP that'll play all the discs I own properly. I just live with it and make CDRs of the ones that don't play properly - wherever possible.

__________________________
Make your choice, adventurous Stranger;
Strike the bell and bide the danger
Or wonder, till it drives you mad,
What would have followed if you had.

Our Panasonic DVD player does the "wobble" thing - our Sony CD player does not.

Go figure...

- GregB

Insert Witty Signature Line Here

TC

A CDS3 will not cure the problem. I have a handful of these non-concentric discs and they are identified by a muted rotational ticking sound in my CDS3.

I have wondered if the noise is generated by rapid back and forth movement of the laser, whilst tracking the data path.

Hi Paul,

No, sadly I've had the cd for some time - I wasn't aware of the problem with a previous cd player - perhaps it was better at dealing with the imperfections?

I made a cdr copy of the offending cd last night and now the problem is gone as the cdr is obviously wll within spec.

Thanks, all,

John