[dknightd]

I keep my discs pretty clean - probably because I'm used to using LPs in the past, so handle only by the edge and center. Sometimes I'll give them a swip across my fleece (in the winter) or my t-shirt (in the summer) to gently wipe off dust that somehow gets on them. These days I mostly rip striaght to my computer and rarely touch the cd again. I'm thinking about putting them in boxes and moving them to the basement, but there is not room down there for them. . . I dropped one once - gave it a horrible gouge - too much for toothpaste to remove. I used a 200 grit wet sandpaper, followed by 400 grit, then 800 grit, then polishing compound (usually used to freshen up car paint), and it seemed to work good as new - YMMV, and don't try this with an LP!.

 

[doomride]

Quote:

Originally Posted by Todd R /img/forum/go_quote.gif The timing of those 1's and 0's as they are received. Do a search for Jitter. BTW, if anyone wants to send me a disc they have a second copy of, I'll treat it with the Auric and send it back so you can compare them. It is removable if you don't like it.

And how do you remove jitter? removing the cd player from the equation and have an EXACT copy of music on a medium that is not prone to physical distrubances and degradation like a CD.

One should NEVER do anything to the surface of a disc if it is visibly undamaged.

 

[Todd R]

Quote:

Originally Posted by doomride /img/forum/go_quote.gif And how do you remove jitter? removing the cd player from the equation and have an EXACT copy of music on a medium that is not prone to physical distrubances and degradation like a CD. One should NEVER do anything to the surface of a disc if it is visibly undamaged.

I'm guessing you're one of those guys that loads all his music onto a hard drive?

 

[lowmagnet]

Rip them to my hard-disk with error correction, and store them lossless. Then I take the disc and store it out of sight in a box in the closet. Seriously, CDs are so yesterday

 

[Mikael]

I definitely don't tweak my CDs, since I don't believe that it has an effect on playback. I'm willing to give the tweakers a chance, though.

We know that reading the data on the CD without errors is a trivial matter these days. For example, when was the last time you encountered a file corruption on your computer, caused by an incorrect reading of a CD? I know what you're thinking now, that data isn't the same as music.

But, we know that the information read from a CD can be reliably stored in memory without error, be that magnetic media or solid state memory. We also know that data can be reliably read from memory (for example DRAM) without error correction and without getting any of that pesky displacement in time. Something like this should illustrate the concept:

Since audio CD players do use buffers, my question obviously is: How can tweaking the CDs have an effect on playback, when there is no direct connection between the D/A and laser? Reading the data correctly into the buffer is obviously not a problem and any time related problems are easily handled by a clocked data buffer between the laser and D/A. So, how can washing, freezing, boiling, de-magnetizing, etc, have all these perceived benefits?

BTW, I'm interested in a technical explaination. As an engineer, I'm not interested in hocus pocus.

 

[Mikesul]

The timing of those 1's and 0's as they are received. Do a search for Jitter.

Ok, but what is the point of a buffer if timing influences the sound? If the buffer reads ahead and just feeds the processor at a steady rate what would your tweaks (always excepting cleaning etc which ensure the ability to read the 0s and 1s) add?

OOPs previous post from Mikael did a much better job of raising this issue than I did. So what is the answer, Tweakers?

 

[Todd R]

Quote:

Originally Posted by Todd R /img/forum/go_quote.gif The timing of those 1's and 0's as they are received. Do a search for Jitter. Ok, but what is the point of a buffer if timing influences the sound? If the buffer reads ahead and just feeds the processor at a steady rate what would your tweaks (always excepting cleaning etc which ensure the ability to read the 0s and 1s) add? OOPs previous post from Mikael did a much better job of raising this issue than I did. So what is the answer, Tweakers?

OK,
There are several explanations & theories about WHY it works, but the point is these tweaks can be heard.

Here's one:
If you read this page from Auric for example, the power supply fluctuation theory sounds very plausible to me.
This theory would apply for any vibration problem, whether caused by discharges from static build up or by vibrations from an internal source (like a transformer or motor) or from an external source.
This is also why different footers under your player or weighting the top of the case can change the sound.

Like I said earlier, send me a disc and I'll treat it for you. Buy or borrow another copy of the same music and try it. Have a friend load one disc or the other in the player so you don't know which one you are hearing and listen.

If you have equipment with sufficient resolving power, good hearing, and the patience to sit down and listen attentively you'll get it.

We've been over this subject many times here and I've offered to treat discs before.
So far none of you Non tweakers have ever taken me up on my offer.
I dare you to try it.

 

[JaZZ]

Quote:

Originally Posted by Mikael /img/forum/go_quote.gif Since audio CD players do use buffers, my question obviously is: How can tweaking the CDs have an effect on playback, when there is no direct connection between the D/A and laser? Reading the data correctly into the buffer is obviously not a problem and any time related problems are easily handled by a clocked data buffer between the laser and D/A.

I'm not sure if buffering and reclocking the data is a common standard these days. If not, timing problems from reading inaccuracies (not data errors) can have an audible effect.

However, even modern, «jitter-immune» DACs like the Bel Canto DAC2 show significant sonic differences with different transports. After all it seems to be insensitive to different digital cables, in contrast to other DACs.


Quote:

So, how can washing, freezing, boiling, de-magnetizing, etc, have all these perceived benefits?

Boiling apparently just serves for halfways fixing a corrupted surface, so isn't meant as a sonic tweak. I can't speak for freezing, since I haven't tried it. Washing seems to have a positive effect in my experience, but I can't explain the cause. The only tweak that could be explained is demagnetizing. From http://www.audioadvisor.com/prodinfo.asp?number=FTRD2:

Quote:

The silk-screened label on an optical disc contains chemical compounds such as iron, nickel, and cobalt. These materials are all strongly magnetic and easy to remagnetize. The reflective information-bearing surface of optical media contains 99% aluminum, but 1% of these same highly magnetic materials! Even aluminum is a weak magnetic material. Amazingly, optical discs actually become magnetized as they play! A magnetic field is induced as the disc spins in the player.

So the explanation is that the alternating magnetic fields from the rotating disc induced into the CD player electronics may cause interferences.


Quote:

BTW, I'm interested in a technical explaination. As an engineer, I'm not interested in hocus pocus.

Of course -- who's interested in hocus pocus!

.

 

[tiggers]

Not to stir thinks up in a new direction, but I wonder if a lot of this discussion about jitter (no one has mentioned WOW yet) might have come from the transition from turn-table to CD.

They are both round and spin, right ? So the same issues that exist for records must exist for playing back on CD? (from the perspective of someone who might not have any technical background to understand why they are different). I just wonder how much of the talk about jitter and such has it's 'tradition' in problems inherent with turntable technology.

 

[Raymate]

A long time ago I did back in the late 80, using a special green pen that you painted on the edges of the disc to stop stray laserlight spraying the inside of the CD player.

And then I used the weighted rings that stuck to the outer edge label side of the CD's

Think I noticed the rings more in a difference in sound.

I got a better result in using sorbathain (not sure how to spell that) feet made by AudioQuest for my CD player.

R

 

[NotJeffBuckley]

No.

 

[edstrelow]

One of the paradoxes of digital sound is that there are claims by some that it "perfect sound forever," (this phrase was actually used in early advertising)versus claims by others, mainly long-time audiophiles who criticized the sound, ranging from "it's harsh' to "it sucks and I prefer lp's."

One of the sources of the problem seems to be a tendency to confuse published specifications for digital recording and playback with actual performance. I mean who would believe the specs on a car, in regard to, say, its mileage or horsepower, without recognizing that actual performance could be dependent upon driving speed and style, type of gas, even age of the vehicle, as it is initially broken in and subsequently broken down. An yet there is a bland presumption by many digital fans, that cd's will always play back on players without problems or degredation.

If this were true I don't see how cd players ever improved, since they were be definition perfect when first put out before the public. So it seems to me if the players can be improved, so can the discs, and some tweaks may essentially contrubute to a better cd.

The recognition of jitter as a major factor in degraded digital reproduction was certainly a breakthrough in legitimizing criticisms of digital sound. However, I still doubt that we have a full handle on the oddities of digital recording and playback.

To be clear, I do not think digital sound is generally bad, in fact I think in most respects I think it is a clear step forward over what was available earlier. (This is not to say that there may be some super lp systems that could knock the socks off at least average- to-good digital systems)

One other 'digital factor" of which I have seen very liitle discussion is the effect of error correction on sound quality. Digital playback uses an interpolation technique for dealing with data with is seriously corrupted.

Relating back to the point above about specs vs actual performance, I have never seen any published report on the the amount of interpolation correction applied in playback on any machine for any peice of music. And by that, I mean actual test data, not hypothetical specs. Of course if it's bad, I can see why it would not be presented. Some very expensive cd transports minimize error correction to try to improve the sound, however, losing some tracking capability in the process, i.e becoming more prone to misstracking.

As for other issues, you have to consider that in addition to problems with the actual digital processing, there are possible issues about the interaction of digital circuitry on analog output. Putting too many demands on the laser mechanism, may rob power from the analog circuit, or introduce additional noise.

I believe that our hearing capabilities are extraordinarily detailed and subtle and just about any little disruption in sound playback and recording can be detected under the right circumstances.

And for the record, double blind tests , which are not be discussed in this forum, are mostly too crude to do a good job on anything other than similarly crude differences.

So anyone who wants to optimize their recorded musical listening experience, as opposed to those who just want to know how little can they pay to get a half-way decent listening experience, is going to have to develope their own critera and use their own auditory skills to determine how to get that optimal experience.

 

[Thelonious Monk]

i tape a seven leaf clover to the top of the disc for good luck

 

[Todd R]

Quote:

Originally Posted by Todd R /img/forum/go_quote.gif ...send me a disc and I'll treat it for you. Buy or borrow another copy of the same music and try it. Have a friend load one disc or the other in the player so you don't know which one you are hearing and listen. So far none of you Non tweakers have ever taken me up on my offer. I dare you to try it.

**silent except for the crikets chirping**

The record still stands, no takers

 

[Dept_of_Alchemy]

Quote:

Originally Posted by edstrelow /img/forum/go_quote.gif I see in your profile that you remove your glasses when listening to speakers for improved imaging. Is this because the glasses interupt the sound to your ears? If so, I am impressed that you can hear such an effect. I know with my main speakers that I do want as clear a path to the speakers as I can get.

Um, since locolization of sound (perception of soundstage) depends heavily on the shape of one's head (look up HRTF on wiki), it is obvious that at least in theory taking off your glasses while listening to speakers is going to improve soundstaging. Empirically speaking, I find that I hear better treble extension when I take off my glasses. So, it works for me.