dampening

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Halojoy,

I am glad that I can at last find something in your post with which I concur.

I agree wholeheartedly that there must be an explanation for the beneficial effects of damping CD players which I have perceived during extensive listening trials.

The difference between us seems to be that simply because I don't happen to know what the true explanation is at this time, I will not ignore what is obvious to me and pretend that it doesn't exist.

Because I wish to have the best possible sounding audio system, I am prepared to invest the necessary time and will continue to carry out such trials, many of which, unfortunately, either don't seem to have any noticeable effect, or the result is no better.

The beneficial result I explained in response to the enquiry regarding CD players, just happens to be one of the 'success stories'.

I hoped my comments might inspire a few others to do the same, and see what they think, because damping CD players is perhaps not an intuitively obvious thing to try, but you have made it clear that you will not bother.
As an enthusiast, I cannot understand your reluctance, especially when I have shown you how to conduct a very simple, free, fully reversible, no-risk test, which would only take you a few minutes.

Sadly, your CD player will not sound as good as it could as a direct result of this, unless the manufacturer has already carried out this exercise effectively (but this would be the first time I have come accross such a situation, although several makers do make an attempt at eliminating some vibrations in CD players), but this is your choice.

Then again, I have not yet tried keeping my CDs in the fridge like you do, as I don't believe that there is any "electrical activity" in CDs to "reduce or eliminate" as you imply.

However, if, as you said, keeping CDs in the fridge does improve the sound of them (for whatever similarly unknown reason), I must try it out for myself, sometime, and if the sound improves, I will adopt that procedure in future, even though I cannot expain the technical reason for any change.

A Happy New Year to you.
 
Hello Bobken

I am glad you are glad. :)

Then again, I have not yet tried keeping my CDs in the fridge like you do, as I don't believe that there is any "electrical activity" in CDs to "reduce or eliminate" as you imply.

However, if, as you said, keeping CDs in the fridge does improve the sound of them (for whatever similarly unknown reason), I must try it out for myself, sometime, and if the sound improves, I will adopt that procedure in future, even though I cannot expain the technical reason for any change.
That was a joke, I do not keep my CDs in fridge!
But I can sometimes be, somewhat, ironical
in my remarks.
----------------------------
You haven't heard about my bad Casio calculator.
Which only gave an "E" when I tried to take Square root of -1.
I then asked, if I should buy me a more irrational calculator,
which could accept irrational numbers.
What is the fault in my Calculator?
--------------------------------------------------------------

But I have have heard guys that do this "tweak". With refridged CDs.
And also found out that having the CD on the metal kitchen sink
before playing them, will make them sound better.
Possible cause: Unloding static electricity from the plastic.

/halo - the joker in the diyAudio deck of cards
 
What is obvious to me is that if the cd mechanism depends
on vibrations and the laser feels more comfortable - damping and
different materials will influence it all the time.

Acryl is very different behaving from all wood types in the
speakers i tried - and this is all vibration for sure.

So all makes sense.

Nobody should deny until he tested the existance of such things.

You sure need a good gear to start with.
 
frugal-phile™
Joined 2001
Paid Member
Re: What should be the logical explaination?

halojoy said:
The day I get the logical described to me (I am old fashion enough
to still trust in the law of Cause and effect)
That day I will start using dampening of digital machines.
To get better "1" and "0".

Just some points halo to point you in the direction of an explaination -- all circuits are microphonic to a certain extent, so damping the things that cause the microphony help, and there is a point in the process of getting the info from the disk into the CD electronics where we are really dealing with an analog RF situation (i pull this info from an interview with Julian Vereker -- someone who really impressed me when i met him). At this point it is not a 1 and 0 problem -- althou they are mixed in the syrup.

dave
 
Halojoy.

Great joke and a very worthwhile addition to this post.

I was completely taken in by you and thought you had become a Disciple of fellow countryman Peter Belt, who does espouse placing CDs in the freezer, but he says you need to write some special message on the bag you place the CDs in, for it to work.

Not yet having tried this, myself (and it is not at the top of my priority list!) I certainly will not make any scathing remarks about the procedure in a public place like this, in case it might inadvertantly wrongly influence anyone.

If I ever get around to trying it, I will let you know!

Wombat & planet10.

Just because I chose not to "rise to the bait" slung out by Halojoy and make any categoric statements which might indicate I think I know all about the reasons for the effects we notice here, it doesn't follow that I don't have any opinions!

I believe you are both correct in your comments, and I expect you were in turn as surprised as I was at the extent of the improvements which can be had with damping CDs.

Any means of giving the 'reading' mechanism an easier time would be almost bound to improve things, in my opinion.

No matter how good the inbuilt systems are for error correction or concealment, the interpolation circuitry cannot possibly make a better job of recreating (or sometimes blanking, where it cannot be successfully recreated) any missing information, which has been lost in the scanning process.

A lot of the time, it does a reasonably good job, although not a perfect one, but why encourage this circuit to work so hard anyway, if there are simple DIY ways of avoiding (or reducing) this?

I believe an analogy with a TT is reasonable in this case, and my TT doesn't care for me jumping up and down near it (and it doesn't have the 'benefit' of any correction circuits!) because that skips and misses bits of information in a big way, when I do that!

Actually, my guess is that in most cases the majority of improvement comes from the elimination of vibration caused to the electronic components, themselves.

You only need to remove a speaker Xover from the cabinet and listen to the marked changes and improvements this brings to the sound, to realise that electronic components simply don't like being shaken about!

In my tests on components, I have come across some capacitors which will make a sound (electrically- through the reproduction system, not from the body of the cap, itself) if you squeeze them, so they must be exibiting some kind of peizo-electrical behaviour, presumably.
Also, many caps will similarly make a noise through the system if you tap them with a screwdriver, or whatever, and I just don't want this kind of extraneous noise in my systems.

Many semi-conductors are definitely microphonic, too, but so far, I haven't noticed much of a problem with resistors performing badly in this way.

In my first CD damping trials, it was over a total period of some two years from start to finish, as I listened to every change individually, to ensure that nothing was being worsened.

This was following reading about someone else's experiences where he had said he had gone too far with damping and had accordingly taken some of the life of the sound away.

To be honest, I never noticed any such effect, and nowadays, I will go through say all of the semi-conductors at one time, and then in another 'session', perhaps try the caps, or whatever.

This speeds matters up a lot, but does provide some control over things, if anything ever seemed to be amiss. Whilst it hasn't yet happened to me as I said before, it would be lot easier to check back on the few components which have just been damped than to retrace all of one's steps back to square one!

Keep on damping, I say, and reap the sonic benefits!!!

Regards,
 
Must be quite easy to test

Must be quite easy to test, if laser reading is changed
for better or worse.
Make a run without damping, record the digital signal.
Same with dampening, record the digital signal.

Use your PC to compare the signals.
No problem with todays digital in/out connections
soundcards and modern computer techniques.

The problem, why this is NOT done,
is probably that those people believing in benefits
of dampening are a bit afraid of the results. :D :D

They have a slight feeling that there is no difference! ;)

Signal is to be taken DIRCETLY from the laser
before error correction.

This can surely be done!
That noone bothers to do RESEARCH of facts
I take as a silent admittance
that I am right in this matter!

As said earlier Turntables should be carefully
dampened and protected from Soundwave feedback in the listenning room.
And recording michrophones have to be that, too.

/halo - does believe in fact - not hypothesis -
- and also believe in Jesus, The Man who Saves :)
 
Re: Must be quite easy to test

halojoy said:
Must be quite easy to test, if laser reading is changed
for better or worse.
Make a run without damping, record the digital signal.
Same with dampening, record the digital signal.

Use your PC to compare the signals.
No problem with todays digital in/out connections
soundcards and modern computer techniques.

The problem, why this is NOT done,
is probably that those people believing in benefits
of dampening are a bit afraid of the results. :D :D

They have a slight feeling that there is no difference! ;)

Signal is to be taken DIRCETLY from the laser
before error correction.

This can surely be done!
That noone bothers to do RESEARCH of facts
I take as a silent admittance
that I am right in this matter!

As said earlier Turntables should be carefully
dampened and protected from Soundwave feedback in the listenning room.
And recording michrophones have to be that, too.

/halo - does believe in fact - not hypothesis -
- and also believe in Jesus, The Man who Saves :)

This is utter nonsence, Halojoy.

The only reason I (and, it seems a few others) don't carry out such a test as you suggest is that it would serve no useful purpose to me/us.
I don't need to prove anything to you, nor to anyone else for that matter, and I don't need any further specious 'technical' proof of what my ears tell me.

I don't know about your strange habits, but I happen to listen to the results (i.e. music) with my ears, and I am very pleased with what I hear with those same ears as a result of carrying out some CD player damping modifications.

If you wish to believe I am deluding myself, then so be it!
You are the loser for being too bigoted to even try a much more simple test which I have already suggested to you.

I still hope that the original enquirer (and any other open-minded reader) on this thread will carry on trying out such modifications for themselves, and not be discouraged by uninformed guesswork from someone who has no practical experience of what this thread is about.

If they do, they will soon realise who is talking sense, and who is not!

You may take my future silence on this topic, at least where any of your posts are concerned, any way you like.
However, the true reason will be that I don't intend to waste any more time on your comments because you haven't apparently made any efforts to try *anything* out for yourself, and yet you speak with apparent authority as if you are the fount of all knowledge in this matter!
 
Digital Data Off The Disc Does Matter.......

Carl (halojoy), you are out of your depth on this cdp debate.
Bob, yes you will quite strongly affect and strongly effect the sound that you are getting out of your cdp by placements and type of damping materials that you are using.
In typical cd players, the currents drawn by the servo stages (spin motor servo, lens focus servo, and lens tracking servo) are high level, noisey, erratic and interdependent (intermodulating).
Due to power supply interdependencies (interactions) and grounds conductors reactances, a whole range of resonances and feedbacks, electrical and mechanical, inter react and cause a variety of distortions.
Because of the reactiveness of a typical cd player system, mechanically, electrically and electronically, the final output sound WILL change according to alterations made to the disc spin/laser reader subsystem.
There are a number of quick and dirty improvements that can be made to a typical cdp, and these include mechanical, electrical and electronic.

Eric.
 
Re: Digital Data Off The Disc Does Matter.......

There are a number of quick and dirty improvements that can be made to a typical cdp, and these include mechanical, electrical and electronic.

Eric. [/B][/QUOTE]

Quite right mrfeedback, and the definition of "experience" is 'having made so many mistakes that there are few left to make'.
I have made quite a few in my time, but at least I have tried a lot of things and have learned a quite a bit along the way!

I wish I knew of someone well-known to quote at the foot of my posts who said something like " Theory has never prevented me from achieving things!"

Regards,
 
Stryder said:
Has anyone here had success with dampening their CD players?
Yes, I think I did.
The things I’ve done (chronologically):

1. I put the player on the bike inner tire (and additional shelf). Generally speaking, the lower resonant frequency is better. Pumping tube, you’re also pumping the sound. I tried the glass, oak and MDF shelves. Glass had the best resolution, the MDF was best balanced, and oak was too murky for my taste. Tried also a few combinations of these. At this moment, I consider the MDF is the best compromise. (Base shelf is made of glass)

2. The player originally had a double aluminum bottom plate. I added one more bottom plate of 19mm MDF. The result: more analog sound.

3. Changed original feet with four solid aluminum, adjustable, spiked feet. This results in more pleasing sound and better resolution. I also tried a few arrangements with three feet, but did not like what I heard.

4. I applied 4mm rubber at all free inner sides of the unit (not at the bottom, because I soldered some parts underneath the PCB, no place to did that). Little strange effect, the sound became cleaner, but less transparent at the same time. It may be better if I applied many small patches at the inner side of the hood (I put one big).

So, I recommend the first three mods. As for fourth, I’m still not sure if it is good or bad. I’m planning to put another bracing on it.

Pedja
 
diyAudio Senior Member
Joined 2002
I STAND WITH BOB.

Hello ,

First of all Halojoy...pay some respect and get a life please?

Bob,

Your experiences on the topic are frighteningly close to mine....a lifetime dedication to the reproduction of music.

Whoever thinks CD is perfect,please think again...it needs at least as much attention to vibration control as a TT and has a lot more problems to boot.

Other than that there are are different other matters that need attention...
Ever wondered what it is you don't like about CDs?

Vibrations are just a minor problem,believe me...

Cheers,;)
 
frugal-phile™
Joined 2001
Paid Member
Re: I STAND WITH BOB.

fdegrove said:
Ever wondered what it is you don't like about CDs?

Everytime i think about this, i think about the big Monty Python boot coming down to squah the music with spurei (sp) going everywhere (because it is unlikely that the Nyquist requirements are satisfied)...

An externally hosted image should be here but it was not working when we last tested it.


dave
 
Anyone with a scientific Approach?

halojoy said:
Must be quite easy to test, if laser reading is changed
for better or worse.
Make a run without damping, record the digital signal.
Same with dampening, record the digital signal.

Use your PC to compare the signals.
No problem with todays digital in/out connections
soundcards and modern computer techniques.

The problem, why this is NOT done,
is probably that those people believing in benefits
of dampening are a bit afraid of the results. :D :D

They have a slight feeling that there is no difference! ;)
-------------------------------------------------

/halo - does believe in fact - not hypothesis -
- and also believe in Jesus, The Man who Saves :)

I really thought someone would have some facts to present
based on research.
Or that someone in this thread was willing to do some tests
to prove the effect of mechanical dampening.

If there is an effect, then it should be possible to show
its existens.

------------------------------

By the answers, I can not find anything that contradict
my assumption:

The problem, why this is NOT done,
is probably that those people believing in benefits
of dampening are a bit afraid of the results.

They have a slight feeling that there is no difference!


The scientific minded people are quite busy
about the "Complex Emitter Follower".
Probably why they are not engaged in this thread.
Or they maybe find this subject somewhat uninteresting.

/halo
 
You are either doing a little trolling or you have no idea about testing for microphonic output on an electronic circuit.

PS: You tap it whilst taking the trace.

CDP transport and electronics benefit from damping period.

Now go away and try it.

PS, if you are neither a troll or ignorant - read this and look at the generic specifications; then question in a really clever logical way why damping might help this complex arrangement. and what the roll of error correction and microphonics might play.

http://www.digitalcentury.com/encyclo/update/cdplayer.html

Gary Lawson SEP B.Eng Hons
 
Re: Must be quite easy to test

halojoy said:
Must be quite easy to test, if laser reading is changed for better or worse. Make a run without damping, record the digital signal. Same with dampening, record the digital signal.

Use your PC to compare the signals. No problem with todays digital in/out connections soundcards and modern computer techniques.

Such comparisons have been done in the past, not with damping mods in particular, but with other variables. More often than not, the data is found to be bit-identical. But this means nothing. You have to understand that musical data is not the same as computer data. With digital music, the timing of the bits is just as important as the value of the bits. Minute amount of jitter are audible. When you consider things in the time domain, digital components suddenly seem to have much in common with analogue.
 
yes, the primary difference between analog and digital systems is the MANNER in which external inputs (vibration, power supply fluctuations, etc.) modulate the output and thus what type of distortion they produce. there is no question however that both systems are susceptible to such interference.
 
frugal-phile™
Joined 2001
Paid Member
Another scenerio where damping could be seen to benefit is: without damping we get more vibration on the disk making the laser mechanism work harder to track the disk. This causes more noise and load in the power-supply degrading the analog section of the player.

You will also note that all the high end players pay particular attention to damping. The Linn CD-12 for instance has a chassis milled out of a solid billet of aluminum into a shape that is intended to immunize it from external vibrations.

dave
 
I'll Say It Again.......

Another scenerio where damping could be seen to benefit is: without damping we get more vibration on the disk making the laser mechanism work harder to track the disk. This causes more noise and load in the power-supply degrading the analog section of the player.

Yup, thats what I said earlier on .
Additionally, digital power supply fluctuation causes modulation of the analogue waveform datastream slicer (jitter), modulation of the clock oscillator (jitter) and modulation of timings in the DSP chip.
Seperated power supplies for servo, digital and analogue audio stages pays big benefits.
Mechanical damping helps, but the electronics require attention also.

Eric.
 
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