Why two numerally identical CDs could sound different?

My very next sentence after the your quote was:

Ryan

 

I was thinking into this direction too and tried some setup variations.
For example :

1)Yamaha CDR 1000 with its own converter and
Yamaha CDR 1000 only as transport with dCS 954 converter

2) Rega Planet with its own converter

Really I could hear that some combinations of transport/converter lessen the perceptual differences.
I would like to note that other people participates on the auditions and we always share impressions.

On www.quantized.com site there are two links that briefly treats with jitter and EFM modulation:

http://www.quantized.com/Introduction_to_CD.htm
http://www.quantized.com/Recorded_Disc_Tests.htm

Maybe this kind of jitter is affecting the performance of the CD players and converters. Who knows?

Regards

 

"My very next sentence after the your quote "

I saw that, but I felt that jitter in the manufacturing process had not been mentioned at this point. It seems like the conversation was revolving around error correction and ADC/DAC jitter. Reference Records has looked into pressing jitter as well.

 

The context of my statement was ways that physical properties of the disc could affect playback, so I assumed that it was implied that I was talking about pressing jitter. (And that writing "slightly malformed pits on the actual pressing master that slightly "distort" the timing that the D/A converter depends on" would make that clear. ) Any jitter introduced downstream of the disc-reading process ought to be equivalent across different pressings, and therefore irrelevant to the discussion at hand. (Unless you're arguing that C1 error correction induces jitter, which is an interesting idea but not one which I've seen data to support.)

Ryan

 

Thanks for the comments Ryan, and no I'm not referring to C1 error correction.

I am just making the case that different CD pressing plants have different jitter rates in their glass master process. I forgot to mention that Mike Hobson of Classic Records also discovered this when he was doing his 24/96 DAD discs.

 

No argument there.

Ryan

 

I finally have on my hands the Hybrid-SACD pressed at Sonopress Germany, now I have the same project pressed at two different plants. As soon as I got the Hybrid-SACD I back loaded it on my workstation and did a DATA compare with my original, no surprise here both, the SACD and my original, have the same DATA. Sonically the SACD 44.1 layer is superb, keeping absolutely fidelity to the original. I would like to remember that in the case of the CD pressed at a plant in Brazil it didn't sound so faithfully compared to the original despite both having the same DATA.
So I have concluded that should be some variables at pressing that could affect the sonics of the copies.