Karmapolice
My family were crack session men in LA and I have been in live touring space for 30 plus years, including Radiohead. Here is my two cents:
There are three things that matter, the original recording sessions, the mastering and mixing, and the final format ("pressing" or CD).
Vinyl does a really good job of recreating the original dynamics of the recording session. When this is spot on, it is really a beautiful thing to hear. I grew up around my family's playing and know what they sound like from 50 years of memory and vinyl approximates this better than digital.
Mastering can introduce a whole set of problems when introduced as part of the mixdown. Tonalities can be adjusted, good or bad, dynamics compressed or expanded, and all aspects of frequencies can be sonically cropped, boosted or altered. Both vinyl and CDs can amplify any shortcomings here, so it is a toss-up of sorts. Also, the term master tape is grossly overused--there are usually multiple tapes out there for all sessions and your vinyl and CD was probably not made from the original master tape but a second or third generation as production was sourced from multiple production facilities. This is why Japanese, British and US pressings can sound radically different around the same artist.
CDs are a perfectly rendered version of the source tape. Garbage in/garbage out--some CDs can vary by tape source.
Vinyl can suffer from the pressing process--the quality and make of the vinyl pellet (there were 13 types of vinyl in its height--only four are still made today), the pressing time in the press, where it stands in the production run, and humidity and temperature of the plant. You could listen to 25 records and hear minute but significant differences in the vinyl. Only 10% sound perfectly correct but when they do, they will slay all other formats. (PS: it has taken me 30 years to collect pristine albums of my family's work).
