- the CD was a simple digitisation of the 1980 analogue master[1]. It was before the "ADD/DDD/AAD" markings started to be used! Hence mastering is not an issue in this case
A CD mastered from the same master tape as a vinyl disc may not have the same signal encoded on it as was encoded on the Vinyl disc.
Mastering, when referring to cutting a vinyl disc, is not synonymous with the process of getting to the master tape. There's quite a lot of processing that can go on between the
1/
4" master tape machine's line output and the coils on the disc mastering lathe. Sometimes it is quite brutal.
The most obvious thing is limiting/compression of low frequency components to stop the cutting head obliterating the grove cut on the previous or next rotation.The language used by cutting room engineers if this happens near the end of cutting a disc could make a navy stoker blush. Then there's RIAA preemphasis and there may be other things done to the signal dynamics to get the whole thing to fit the physical parameters that are permissible on vinyl. Fitting a lot of material onto a single side of vinyl sometimes requires reducing the dynamic range of the entire recording just to make physical space.
Going to a cutting room to watch your disc being cut from your precious master tape is a bit like going to watch sausages be made from the pig you hand reared.