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In Reply to: Humour me, because i am really dumb ... posted by Christine Tham on August 14, 2005 at 22:17:19:
"Yes" -- I am positively sure beyond all reasonable doubt that prolonged playback of the DVD sides of DualDiscs in my DVD players, and the CD sides in my CD players won't have any negative impact whatsoever on the lifespan and reliability of my respective players (i.e. compared with a "Redbook" "Compact Disc").But I'll go further than that: If I do play the CD side of my DualDisc in a player (or CD-ROM drive) that has read issues, then I am equally confident that NO lasting physical damage will occur.
Moreover, if any of my players do break, it will most likely be the laser failing -- JUST as is the case with ALL the other 'shiny disc' players I've owned since 1983.
Your Panny was an exception -- i.e. it's motor mechanism failed with ordinary DVDs/CDs because the rotating part itself was substandard. It would have failed whatever you'd put in it. Therefore any statistical correletion you attempt to apply -- presumably based on the variable "rotational inertia" -- regarding DualDisc reliability [in your player] is utterly meaningless and irrelevant.
Follow Ups:
Some excepts from the Denon DualDisc FAQ, available on the Denon web site:*** The non-DVD side of the “DualDisc” delivers the 2 channel recording; however it does not meet the Compact Disc Digital Audio Specification and therefore does not bear the CD logo. ***
*** The DVD video/audio contents on the DVD side of the “DualDisc" do not guarantee reproduction by Denon DVD players/changers and universal players. ***
*** Since the audio side of the DualDisc does not meet the Compact Disc Digital Audio specifications found in the industry “Redbook Standard”, the data constituting the audio portion of the disc may not be read by some CD players/changers and recorders, DVD players/changers, universal players and Super Audio CD players. Even though the audio side does not meet the Compact Disc Digital Audio specification, some Denon CD players/changers and recorders, DVD players/changers, universal players and Super Audio CD players may read and interpret the audio side of the disc while others may not. The non-DVD side (audio side) of a “DualDisc” will be not able to play in a slot-type DJ or car audio players. Also, the non DVD side of “DualDisc" may become scratched or abraded with attempted playback in slot-type CD players. ***
One thing I will grant you - Denon does not specifically prohibit you from playing your DualDiscs, nor are they threatening to void your warranty if you choose to do so. But then, I also don't see any specific confirmation that your player is "certified" to play DualDiscs. So in other words, it's entirely up to you.
As for your comments on my player, you are clueless as usual. The documentary evidence is quite conclusive - but if you choose to refuse to accept the facts then tough.
You are blowing your intellectually arrogant smoke as usual Christine.
So then, answer me this: To justify your reliability hypothesis, can you tell me exactly WHICH mechanical variable(s) are you basing it on?But you can’t. Because quite simply, you know that you don’t have a clue about mechanical reliability analyses and statistical correlation; MTBFs, FMEAs etc.. They are complex subjects that professional mechanical & production engineers spend months studying and as well as applying in practice, before they release a product to market.
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There should have been long term testing done and CLEARLY this was not done or there would be not manufacture warnings and NO upcoming Dual Disc compatible DVD, SACD and CD players.They messed up and you are willing to subject your valuable equipment to their incompetence. And attack anyone who is not willing to take the risks you are.
> > There should have been long term testing done and CLEARLY this was not done. < <You are totally wrong there. The DualDisc consortium undertook a whole matrix of test scenarios. Many different players. A full reliability study using many independent samples. They know *exactly* what to expect in terms of reliability.
But had they done "long term" testing they would have foreseen all the problems and issues way before they happened.One does not design a product to work at the maximum tolerance (1.5mm) and slightly beyond and not expect something to break! That is just not logical.
There is a simple fix coming though DualDisc compatible CD and DVD players that will move the maximum tolerance to about 1.8mm to cover slight manufacturing defects and variances.
The DualDisc consortium was totally blowing smoke and you are willing to risk your equipment, as you actually believe them and not the designers who made your equipment, why? The fact is the DualDisc consortium rushed DualDisc to market without adequate testing to try to combat illegal downloads by offering extra content they cannot get on the web.
Until you can get a DualDisc compatible DVD player you are playing DualDiscs totally at your own risk.
Teresa: I suggest you get the facts directly from the DualDisc consortium (re. their extensive pre-production QC testing matrix). If you won't do that, then please put your pipe down.b.t.w. Not one manufacturer says how a machine can "break" by playing a DualDisc: Not regarding 'rotational inertia' issues. Not regarding 'laser focussing'. Not regarding 'error correction'. Not regarding disc 'thickness'. Not any of these.
Granted, some disclaimers do allude to the possibility of one of the sides getting scratched by a slot loader's pull-mechanism. But I'm not worried about that. And FWIW, the SUV'S slot-loader I did try the Keane title plyed it fine; it did not get stuck; and it did not scratch the top side of the disc. (I can't speak for other people's experiences with slot-loaders of course).
The DualDisc consortium or the people who make our DVD, SACD and CD players?I choose caution and heed the warnings of the equipment manufacturers and reframe from putting a DualDisc in my DVD-Audio player.
You on the other hand throw caution to the wind and believe the DualDisc consortium and actually play DualDiscs in your DVD-Audio player.
It's a choice and I choose to be safe and that's all it boils down to.
Martin, you've laid claim to having an engineering background. Change out of your DuaDisc cheerleader uniform for a few minutes and try to think like an engineer.Earlier you brought up to Christine > > mechanical reliability analyses and statistical correlation; MTBFs, FMEAs etc.. < < Let's talk about that.
MTBF is an average, typically determined through prior experience and estimates based on typical usage.
FMEA is a predictive analysis based on the system's intended use.
Once you take a device outside of its design envelope, MBTF and FMEA are pretty much useless!
As an example - the motor in my Yamaha racebike contains many parts, most of which have MTBF ratings based on typical usage. I expect that FMEA (or something similar) was performed in order to determine spares allocation and the like, but again, this would be based on typical usage! Yamaha warrants the motorcycle to be reliable in a typical-usage situation.
The way I use the motorcycle is far from typical. Since it is a race machine, I run the motor near redline (for maximum power output) almost constantly. I am not exceeding the tolerances, in that I do not exceed maximum rpms allowed, but since I am running it near maximum tolerance at all times, it is not typical usage so MTBF means NOTHING! Since I am pushing the motor as hard as it can be pushed without exceeding tolerance, I expect things to wear out more quickly, go out of tune, lose efficiency. This means I am frequently doing maintenance and replacing parts that would not have worn as quickly if I were using the product at less than maximum tolerance. To that end, Yamaha does not warrant the motorcycle when it is used under race conditions.
So - the disc players we have today were designed for a typical usage scenario of CDs and DVDs which are at, or very near, the specified 1.2mm thickness. MTBF is based on this. Any FMEA would be based on those design parameters. There is a maximum tolerance of 1.5mm for disc thickness, but since it is maximum, there would not have been an expectation that many discs would reach maximum. In the opposite, in fact - a close-to-1.5mm disc would tend to be a rarity prior to DualDisc.
Now comes DualDisc, with a MINIMUM specification of 1.42mm, up to 1.5mm maximum. I'll be generous and assume for discussion purposes that there are no longer any discs that exceed the 1.5mm maximum.
1.42-1.5mm is within the tolerance range, but it's MAXIMUM. Feeding a player designed for 1.2mm discs a steady diet of discs at maximum tolerance is outside the typical usage scenario, which means, just like the situation with my racebike, that MTBF becomes meaningless, and any predictions based on a FMEA would be useless.
Again, just like my racebike situation, it's reasonable to assume that regularly running the player at or near its maximum tolerance may cause parts to wear out more quickly, cause alignments to drift, and create maintenance or replacement situations that might not have occurred if the player hadn't been regularly run at maximum. Given this quite reasonable assumption, player manufacturers are well within their rights to say that they will not warrant the players if the players are used in this manner.
So, until the player manufacturers have had the opportunity to do long-term testing, and FMEA with new parameters, Teresa is absolutely correct - you are incurring risk by playing DualDiscs.
BTW, if you think that the DualDisc consortium did long-term player reliability testing (as opposed to simply testing for a minimum playback compatibility level on various players), then YOU are the one smoking something, and you should put the pipe down.
/ . . . /"Meridian does not guarantee that the CD-compatible side will play without audible errors in all players. However, attempting to do so will cause no harm or damage whatsoever to our players."
/ . . . /
[And now re. the THICKER & HEAVIER DVDPlus: ]
"DVD-Plus. Meridian is also aware of another 2-sided DVD-based disc format called DVD-Plus or OneDisc, which is thicker than DualDisc (typically 1.55mm). In the few cases we have tested, both CD-compatible and DVD-compatible layers appear to function in all our players, and no harm can come to our players by trying them."
Meridian's information about DVDPlus is incorrect:
Maybe Meridian did their own measurements.b.t.w. I have a DVDPlus album (Kasabian) and it feels thicker than my DualDiscs. (It plays fine in all my players.)
You don't own a Meridian, do you?
You are being silly.
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The CD Blacklight is a 0.2 mm thick mat that sets on top of a CD or DVD, the disc with the mat on top of it is still thinner than a DualDisc! Yet after using it for about six months my transport stopped working. I would blame the thickness more than the extra weight but I am sure both played a part. Not only that I tried the mat in the DVP-S9000ES SACD player which replaced the Audio Alchemy and it caused the transport to make grinding and clanking sounds. I took it out tried it again with the same horrible noise. I got rid of the Audioprise CD Blacklight Mat.This is why the CD/SACD/DVD-Audio equipment manufacturer warnings make perfect sense and are totally correct.
I personally will not play a DualDisc on my DVD-Audio player. When I am able to purchase a DVD-Audio player that is DualDisc compatible I will try one but not until them.
I wonder what excuse you will make when your DVD-Audio player dies playing DualDiscs.
Happy listening (while you can),
Teresa_____________________________________________________________________________________________
AUDIOPRISM
CD Blacklight
The CD Blacklight disc is comprised of multiple laminations of synthetic materials that are laid-up in a constrained layering scheme, which provides very good damping characteristics. Conductive carbon is used on the interface surface to guide electrostatic buildup (each CD spinning inside your transport generates a static charge just by rotating in air) away from the disc. And AudioPrism's proprietary phosphorescence layer glows further to "bias" the laser, further reducing the effects of jitter. With CD Blacklight, music is more alive, neutral and detailed."
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