Japanese Zep CD's-the sound remains the same

compact discs and dvd's are different depending on label and facility specifications. even the manufacturers of the plastic and metal used to make the discs are different in terms of standards. the color of the metal used even changes the sound(those gold discs aren't gold for no reason). contrary to what many believe, a cd isn't made to last forever, and a good deal of how long it lasts and how long it sounds good is determined by the standards it was made under. rot and loss of information are two real problems that do exist in both formats. there are even solutions and polishes that aid discs that exibit errors. masters and dlts are affected by climate and handling as well. the average cd now costs less than 40 cents to make and a dvd9(dual layer)is well below one dollar. gold as opposed to silver adds significent cost and it isn't just because it looks cool. the playback levels set for volume etc. etc. it all has just as much effect on sound or more as ditching one 99% pure copper wire for other one.

There are occassions when the same source tape can be mastered so that it sounds different e.g louder or even when it's tweaked in some fashion (for instance the Nick Drake remasters have different eq's/mixing)but for me that is remastering.
In the case of the Yes Japanese discs (which are HDCD's)there is a noticable difference-not least in volume.

However Jay Douglas please pay attention to this-I have both the Grey box set and Physical Graffiti on Japanese import and they are IDENTICAL.

When you've heard both get back to me on the subject or alternatively give us a detailed analysis of what Zep discs sound better or are the same.
Your post is ambigious at best and does not nail down the specifics.

I have no difficulty believing that manufacturing differences exist, nor that these differences affect the lifespan of CDs (though I've yet to have a single CD go bad on me in 20+ years). I also can see that they might affect sound quality in a poorly designed CD player (with marginal tracking, error correction, and jitter suppression).

What I would like an explanation of is how this effects the sound. Has anyone shown that errors make it past the error correction coding ? Has anyone done double blind proofs of difference with a reclocking DAC ?

i've been involved in the production end of audio and video for two decades and know the faciility standards from one manufacturer to another are not the same..... and it does have a direct impact on the sound and picure of discs even on the same title....as well as the shelf life....google and research......in many ways there are similarities to the glory days of vinyl.

one more thing and i'm out....there are numerous manufacturing and stability studies that have been done on optical discs new and old. most of the time you do get what you pay for with software....even of the prerecorded music variety. there are things hi end hardware can't cure alone. enjoy zepplin no matter matter the country of origin