I've been wondering for quite some time now.

Obviously there is going to be variation in playback quality between the el cheepo no name CD player and premium/professional models, though one might think that the digital nature of compact disc audio should guarantee identical playback everywhere, if we exclude output filters, DAC quality, SNR etc.

While my garden variety car CD-player can get skippy as hell, I've seen standalone CD players like those used by DJs (usually Pioneers where I'm from) that seem to be so robust that they can handle whatever is thrown at them. I mean, I've heard discs that were so badly scratched to the border of total unplayability, being played back flawlessly (or at least without audible skips or artifacts) on standalone players meant for professional use.

Therefore I assume there is such a thing as industrial strength CD playing equipment, for professionals who cannot afford to have anything spoil the continuity of audio playback. One might argue that a pro perhaps devotes extra effort to keep his CDs in mint condition, though I have seen many examples of the contrary, thus I assume the hardware also plays a major part.

So my question is, what distinguishes premium models from staple CD players, with regard to robustness and reading capability?

Is it:

• Better laser quality?
• Greater vibration resistance?
• Better post-processing circuitry (interpolation, etc)?

Please share your knowledge or theories if you will.

I don't see what's so obvious about it. Find a blind test where people can tell the difference between an el cheepo player and a premium model. Some people have tried...and failed.

As for a premium player being able to read some discs better (e.g. dealing with a scratch better) than others, this is can believe since I do have experience with players that will pop/skip with a disc when other players can read it without (or so I think) issue.

I'm not sure that "the more expensive the better" applies for CD-players really. At least for CD-ROM's I'm very pleased with the error-resistance of my Lite-on drives compared with pretty much any other drive I've tried, and these are pretty cheap.

Personally I think the key factors here are laser-quality and the ability to recover from C2-errors, but really you should ask greynol - He's an expert on the subject (and will probably flame something in this post anyway).

OK, I'm not saying it will be ABXable, nor am I trying to start a "more expensive sounds better" thread.
If only theoretically, professionally oriented equipment will probably have optimized circuitry for post-processing, even if the practical benefit thereof may not be perceivable.

Let us focus on the reading capabilities.

To me it sounds like you are talking about the ability to read scratched discs... A disc can be scratched and still be read perfectly (even by a cheap player) - Also a disc can be so badly scratched that it cannot be read at all by pro-players - it all comes down to the type of scratches on the disc. If they are surface scratches - You won't be able to retrieve the missing information no matter how "pro" you go. If they are silver-side scratches, usually there's a good chance they can be recovered and probably read better by some players than others.

That said, if the disc is NOT scratched, any player should output the same digital bits.

Well yes, I am mainly referring to the ability to recover the audio from scratched CDs, but if it were for the dependency on the types of scratches only, I wouldn't be asking.

I was intrigued to see that a standalone player at my dance studio could handle a uber-scratched CD without (perceivable) issue, whereas my personal car stereo and my Plextor drive (that I had at that time) struggled.

Therefore I asked myself if it is possible that extra mechanisms for robustness are built into players that are used professionally, in the same way that other products have differences depending on if they are consumer grade or industrial-grade/strength-classified.

If this is a false assumption, no problem with that, I'm just trying to understand what I have witnessed several times.

What do you mean by silver-side scratches? Are you referring to the non-label side, from which the disc looks silver? Your statement is confusing because the silver layer is actually on the label side, under the label.

Just take a look at a Denon DN-C635 or Denon DN-C640.
You get for 600€/950€ really good gear that beats any High-End stuff in engineering quality and features.

The difference between Consumer and Pro gear, is reliability, long term service, robustness in any way and you get what you pay for.

It seems the difference with those is actually features. Features the OP doesn't need, like XLR balanced outs and other ports, and a plethora of software functions that you can probably get with a laptop.

To the OP, are you looking for a CD player at this point? Why can't MP3's or even flacs work for you? I myself have been looking into netbooks for music playing, seems like for a bit more than an iPod you get to play pretty much every codec under the sun, and have plenty of remote options too with bluetooth, RF or even infrared, and digital SPDIF output.

Yes as opposed to the label-side scratches.... I don't know what else to call the polycarbonate side in a more human way ?

OP: What is your goal? Do you just want to have a ripped copy of said CD without any noticeable skips? In that case, you should just try different drives and different rip settings. Once I was in the same situation as you, where any CD player would skip badly on a track and EAC seemed to be of no help in secure modes - However WMP ripped it without a problem. I think that I was able to rip it using burst mode in low speed, and this mode has actually helped me rip a lot of discs that I had problems ripping in other modes on my Lite-On drives.

Edit: That-is, I think you are focusing too much on a post-processing theory. I can't tell for sure if there's any, but if a hardware player can perform post-processing, so can software. AFAIK it has been discussed previously how to remove skips/pops from bad rips both automatically and manually.

No, my goal is not to find a personal solution for seamless playback.

I started this aiming for a theoretical discussion for hardware that reads optical media. Not losslessly compressed, nor supported by software post-processing.

Once again, the question is whether equipment intended for professional use offers features not deemed necessary (or deemed overkill) for regular or even high-end consumer electronics, with regard to playback capabilities (not ripping), that would justify my observations.

I can imagine that "pro" equipment (possibly) comes with:

• sturdier chassis
• better service plans
• DSP effects (equalizer, ability to tinker with pitch/speed etc, crossfading capability) [this is not to say that these are not available in very affordable consumer-grade players]

...but I'm wondering if any extra playback-related features are implemented as well, to justify observations such as:

• Never heard music played at dance competition skip (this would be a disaster for competing couples)
• Never heard serious skips in night clubs
• Have had incredibly badly scratched CDs play back without audible artifacts on standalone DJ deck players (CDs my CD-ROM and car player would choke on)

I would be interested to find out if these are statistically valid observations, or if the sample is not representative of the whole.

I've heard skips several times on the radio when they are forced to use CD-medias

Whle it may seem intuitively obvious that there is going to be variation in playback quality between the el cheepo no name CD player and premium/professional models, there are no such guarantees in real life. In fact, it has been documented that there is a highly-regarded $multi-kilobuck CD player that hides a CD transport taken from a $60 boom box inside its millled aluminum billet chassis. In other cases megabuck optical players are just rebadged product that sells under its maker's name for a few $100.

Output filters are now just a subfunction of the DAC chip, and DAC chips whose performance exceed the needs of the ear or any real-world recording cost under $2.00 . One of the finest chips around for building output buffers is under $0.50 in production quantities and is also vast overkill. Diminishing returns has set in very strongly in most conventional CD player that cost even just $100 in most stores.

Mass market products are all prone to a process called commoditization. Think about sugar. Is there even a really signficant market for high end granulated sugar? Not so much. Why is this? The product has been made so long and is so completely standardized and pure in its basic form that a 5 pound bag of granulated sugar is what it is and that is granulated technical grade sucrose, plain and simple.

It's worth noting that, while professional gear should be (and usually is) built to withstand far more use and abuse than consumer gear, one issue is that (in the UK at least) consumer gear comes with a minimum guarantee of 1 year, while professional gear typically comes with 90 days or similar.

Cheers,
David.

Please, share the knowledge and website with photographs or other forms of proof, please. if you are uncomfortable with sharing in public, you can PM me.

This was posted on one of the DIY audio sites a month or two back.

http://forums.vr-zone.com/audiophiles-htpc...lone-story.html

http://www.audiostereo.pl/forum_wpisy.html...36475&p=1#k

and this one was on one of the AV forums:

http://www.avrev.com/forum/blu-ray-players...adged-oppo.html

This is not professional gear, that is "Audiophile High-End Gear".
That's typical for "Audiophile High-End Gear" companies, they sell you 4000€ cases with shiny buttons and 50€ electronics.