Am I imagining things?

[Andrei]

My current disc spinner is a Cambridge Audio 650BD. Very competent player but not really up there, and I am currently saving for something special for my SACDs. About a year ago I bought some Sorbothane feet - Audioquest's Q-Feet, I think they are called. I suppose it made a difference, but certainly nothing that my old ears could pick up. 'Oh well' I thought, 'those Q-Feet were not expensive' and I left it at that. Last month I was cleaning out the shed and I discovered an off-cut of some Dynamat. It measured about 3 inches by 3 inches. For those who do not know Dynamat is a dense butyl substance that is used for sound deadening in trucks and cars. I have used it to great effect in my old Nissan Maxima. In fact that project of making Hi-Fi in a motor car would make for another story. For a bit of a lark I decided to stick this piece of Dynamat on the top of my Cambridge Audio. (As an aside this dynamat is not a thing of beauty, but the placement of my CA 650BD means it is out of sight). Did it make any difference? Well I am here to tell you that it did! I am only putting this in this forum because (1) I am pretty sure I am not the only nutter here; and (2) I trust you guys as gentlemen not to report me to the psychiatric unit.

It is difficult to describe the difference but here goes. First, it was an improvement; second, I think there was a warmer sound; and third the soundstage seemed more coherent. Not big differences, but enough to be noticeable. I do doubt this and I am trying to rack my brains (brain Andrei, brain singular, you only have one) as to anything else that I have done that could have contributed to this improvement. What I don't understand is how I can notice a difference with the dynamat and not with the sorbothane. Man is confused.


Who loves you the most, your wife or your dog? It is your dog and this can be proved with a simple experiment. Take your dog and your wife and lock them both up in the boot of your car. Open it up after one hour and you will immediately know who is happier to see you.

[DSJR]

The main issue for cheaper disc spinners does seem to be tinny casework or a too-lightweight construction in general. The top Cambridge 840C of a few years ago was claimed to be sonically improved on CD replay via the enclosed transport if the case was damped and/or mass-loaded. Even more solid machines like the top of the range Arcam FMJ model sounded better on a sympathetic support and I'm sure the data extraction from the disc may well be measurably improved by such methods and if you can hear the difference too, then it's important :)

Thanks for passing on your findings.....

[Oldpinkman]

Oh no. I have a stock of green marker pens if they're any use to you :rolleyes:

[StanleyB]

Unlike a PC CD-ROM drive, a stand alone CDP laser won't go back and reread a track whilst the CD is spinning and data is being extracted. If there are errors in the data then the Reed-Solomon error correction will kick in and substitute the missing data for a software generated approximation of what is missing. Of course this corrected data is unlikely to have the all the information correct, which is reflected in what is passed further down the audio chain.
Vibrations to the CDP can trigger off the error correction. The CD mechanism itself is mounted on a vibration resistant platform but that is not as good on some mechanism compared to others. So adding some sort of additional vibration combating method is not a bad idea. It can reduce the number of error correction intervention by the Reed-Solomon software code, and thereby produce better data accuracy.

The green pen does not work on CD pressings from the last 15 odd years. Since the problem with the oxidation of the aluminium layer was discovered CD manufacturers have employed new fabrication methods. But some users of that pen have translated the ineffectiveness of the pen on more recent compact discs into a failure of the product to work. Kind of like pouring 30 year old leaded petrol into a modern car and wondering why the car engine is misbehaving.

[Oldpinkman]

I wouldn't dispute for a minute that mechanical inteference can affect the data read from a cd, and error correction can affect the sound. I am a lot less persuaded on the green marker pens (Very vivid memories of a session in a hotel in West Kingsdown, 25+ years ago, sponsored by I forget which mag, with all Linn Naim gear, and a felt pen session).

The issue was that Andrei wondered if he were imagining things. We concluded there was a lot of wishful thinking going on with the green marker pens at the time. The test is simple. Pick a CD you like in excellent condition. At the same time every day for the next 10 days, get Mrs Andrei to play that for you, without you knowing if there is a support on the player or not. Get a simple random number generator to produce the list of 10 A's or B's, and your beautiful assistant makes use of that list, whilst practicing her best poker face, to decide whether you are hearing A no support, or B support. Listen for 15-20 minutes. At the end mark that listen A or B.

If you are consistently right, and you know it without having the marked sheet back, then its for real for definite. If you score a high percentage accuracy, but not over 80 its probably accurate but probably doesn't matter much Worth £100 but not £1000. If you can't score better than random, you are suffering little green man (or even little green pen) syndrome :)