I’ve often wondered about this as well. It might be one of the possible explanations of sonic differences between different copies of the same record (sometimes even with the same matrix numbers). But there are probably too many other variables to make valid judgement calls.
However, there’s one possible case where most variables don’t apply. As most jazz vinyl collectors know all ’original’ Blue Note records were pressed by the Plastylite company. They were renowned for their pressing and sound quality and can be easily recognized by the so called ’ear’ in the run out grooves (in fact an inverted & stylized P). When Blue Note was sold to Liberty in the mid 60’s the pressing arrangement with Plastylite was cancelled and manufacturing immediately went to Liberty’s own pressing facility in New Jersey (and thus no more ’ear’). But the new owner continued to use the same plates mastered by Van Gelder, so any sonic difference between the Plastylites and Liberty’s can be attributed to the different pressing facilities, each using different stamper machines and procedures. And - most likely - a different vinyl compound.
I’ve compared these pressings of many Blue Note titles and have been unable to detect any sonic difference. This might be of interest to some of you, because there is a huge and still widening price gap between Plastylite and early Liberty pressings of the same titles. If sound quality is your main target (apart from the music itself of course) and not the possession of an ’earliest pressing’ trophy, you can save a lot of money without sonic penalty by getting these Liberty’s. As prices of the Plastylites have gone insane, the Liberty’s are picking up in value as well. On eBay they’re currently being offered less often than the Plastylites, which suggests to me dealers are hoarding. Within a year I expect to see an avalanche of Liberty’s at Plastylite prices......
Anyway, in my humble opinion the sonic impact of the vinyl compound itself is negligable and indeed a narrow corridor for choosing your records.
However, there’s one possible case where most variables don’t apply. As most jazz vinyl collectors know all ’original’ Blue Note records were pressed by the Plastylite company. They were renowned for their pressing and sound quality and can be easily recognized by the so called ’ear’ in the run out grooves (in fact an inverted & stylized P). When Blue Note was sold to Liberty in the mid 60’s the pressing arrangement with Plastylite was cancelled and manufacturing immediately went to Liberty’s own pressing facility in New Jersey (and thus no more ’ear’). But the new owner continued to use the same plates mastered by Van Gelder, so any sonic difference between the Plastylites and Liberty’s can be attributed to the different pressing facilities, each using different stamper machines and procedures. And - most likely - a different vinyl compound.
I’ve compared these pressings of many Blue Note titles and have been unable to detect any sonic difference. This might be of interest to some of you, because there is a huge and still widening price gap between Plastylite and early Liberty pressings of the same titles. If sound quality is your main target (apart from the music itself of course) and not the possession of an ’earliest pressing’ trophy, you can save a lot of money without sonic penalty by getting these Liberty’s. As prices of the Plastylites have gone insane, the Liberty’s are picking up in value as well. On eBay they’re currently being offered less often than the Plastylites, which suggests to me dealers are hoarding. Within a year I expect to see an avalanche of Liberty’s at Plastylite prices......
Anyway, in my humble opinion the sonic impact of the vinyl compound itself is negligable and indeed a narrow corridor for choosing your records.