If a compact disc is really scratched up does this affect sound?

GameStop - a used video game retailer in the US - does this all the time with their new games. They take the discs out of the cases, put the cases on the shelves and then store the discs somewhere. Yet, since they're opened already, they should be considered used. Not to mention they plaster stickers all over the case. That's why I don't buy any new games from GameStop. Even worse is that they let employees take games home to play and they just re-seal them and sell them as new, even though they could be horribly scratched by a stupid employee.

 

Me either, but a brief guess is that the polycarbonate (typical melting point 230-300 degrees C) softens enough in the boiling water (100 deg.c) for the edges of the scratches to blur a bit. Or of course it might just be placebo effect.

I find I don't need to make a scratch invisible, or flat, to get the thing to play again but just make the edges less sharp. It's obviously a refraction/reflection thing.

 

This thread is ridiculous. Compact discs will never scratch.

http://www.stevehoffman.tv/forums/showthread.php?t=180055

 

I tried some Meguiar's Scratch X (car polish) on a non-important CD that had rub marks that dulled the finish, and it shined the finish back up; however, I didn't notice any improvement in the hairline scratches on the disc.

 

Scratched CD's have never been an issue for me Bill. In fact, some of the best sounding pressings I have come from the scratched CD's over their perfect looking duplicates.

 

Truly, a WTF moment...

I don't know how it happened. I recently opened up by backlogged sealed "Cheap Thrills" SACD yesterday.

It would only play the stereo SACD layer. I ejected the disc and it had this scratch on it. About three inches long!

It took forever for the SACD to load by the way. Now it won't play much at all. All my other single layer and hybrid discs play fine.

Now, the question is: Novus or toothpaste? Which toothpaste?

 

I tried the toothpaste method. Truly, I think I have a defective disc.

I'm convinced there is no surround layer!Cause when I modify it for that layer on my player, the disc is not recognized!

The stereo layer stops halfway through. [sigh.]

 

Find a local store that has a disc polishing machine. It might be your only hope at this point.

BTW, I have read that SACDs made in Germany have an extra coating on the read side that makes them nearly impossible to buff. I don't think the Sony SACDs are like this so you should be OK.

Kevin

 

I don't think you have that correct. The early Sonopress discs had a warning about using disc treatments (Auric Illuminator etc). The surface reacted with the treatments. They ended up changing it.

Nothing will stop that grinding/buffing/polishing wheel.

 

I was told that the reason that the Sonopress SACDs had that warning is because there was a thin top layer that would react to the treatment and possibly render the disc unplayable. I think I read somewhere (Audio Asylum?) that someone buffed a Sonopress SACD and removed the layer, destroying the SACD.

 

Toothpaste is far too abrasive to polish plastic. Use a good quality plastic polish. If you know someone who owns a Lamborghini, ask him what he uses to polish the plastic parts on his car - I'll bet he doesn't say toothpaste.

 

I am a big NOVUS fan. If used correctly you would ahve a hadr time telling if the disc was new or old mind you that depends on the depth of the scratch.

 

Popped open my new Fritz Reiner/Mussorgsky RCA Living Stereo SACD this weekend and some idiot had put the security plastic thingy on the inside of the bed where the disc rests (instead of on the outside, in between the label and the jewel case, where it belongs). So naturally the disc got scratched, rather badly in fact.

What is the boiling in water method? Sounds serious.

 

As noted, if the scratching is really bad, the player will interpolate and/or mute.

Otherwise the answer is "it depends."

If you are listening to the analog output of the player while the laser servos are going nuts trying to read the disc, the servo draw on the power supply will fluctuate wildly and contaminate everything else.

Found that out during a listening test of 2 players with identical CDs...but one was scratched. FFT analysis clearly showed noise artifacts with the scratched disc, but not with the pristine disc.

Now if you are listening on some ultra expensive built-like-a-tank unit with isolated power supplies for each little circuit, maybe that wouldn't happen. And if you're using digital output, I would think if the scratching is light and doesn't cause interpolation or muting, the signal should be "perfect forever."

 

The first part seems to be what I remember too.

I had not heard of the second.

 

Great information.

 

Am I opening up a can of worms by evoking The Disc Doctor?!

http://www.stevehoffman.tv/forums/showthread.php?t=16278&highlight=tracking+errors&page=3

http://www.skippydisc.com/pgs/Home.php

 

Bump on disc doctor...

 

I got a replacement "Cheap Thrills" SACD. Plays great. Bump on Disc Doctor for original disc...

 

Sure doesn't do it any good.

I have one gold cd with concentric circles and it still sounds ok, but I am pi$$ed at my Denon CD player for scratching up my Jimmy Page Deathwish CD.

 

I'm not even sure how the 'transparent' SACD layer gets into the disc, but it's clearly closer to the playing surface than the silvered layer is. (I'm guessing a Hybrid is basically a dual-layer DVD)

The disc-doctor type machines are very abrasive and I expect they'd not be good for SACD. A resurfacing might be OK if done carefully. If I had one that didn't play, I'd try the Novus 2 on it.

I have a really scratched up SACD, a Dylan, from a clearance bin. The SACD layer plays perfectly, though the disc is clearly G and looks like Tony Hawk's been popping wheelies off it. SACD has improved error correction over CD.

 

To repeat my report, my toothpaste method didn't work.

What about Novus 2, then MOFI Shineola?!

 

Real world, I don't think the voltages fluctuate to the point where the circuits are being strained. But what does happen is that if the CRC error correction fails, you start to get clicks and pops. I've heard really bad CDs have very subtle "click-click-click" stuff way in the background, even down -60dB to the point where it gets masked by most music.

I concede that the construction quality of many (if not most) CD/DVD players these days is so cheap, the first thing they skimp on is power supplies. It's shocking, how much empty air is inside most disc transports these days. I don't doubt that a better-made player will recover faster from disc errors and interpolate them a lot better.

 

Novus works great, imo .. and a must for pinball machines as well

 

Which Novus to get for scratched CDs? I understand there are different numbers attached to them, fort different grades.