How much does vinyl formulation have an influence on overall sound?

The quietest pressings we've seen have come from QRP which is owned by Acoustic Sounds.
Its not the vinyl though- its how the pressing machines are damped so as not to shake or vibrate as the vinyl is being pressed.
In mastering different projects that went to different plants, what we've seen is that the mastering quality has more to do with the final sound than the pressing plant. For example, United has a mastering operation, which sounds rather flat and its not unusual to get some surface noise. But if a different mastering house is use and United is only used to press the LP, the results are pretty good. In all our projects we've mastered, no pressing plant so far has indicated any other options other than thickness.

Also the quality of the vinyl and the method in which it is stamped determines whether there will be sporadic drop outs and noise (chunks, potholes, pits) in the groove walls. Some of this depends on the formulation of the vinyl compound, whether it contains recycled materials, etc. Even with a given formulation, there will be batch variation of the quality of the premelted pellets from the supplier. I have several pressings that, except for a few sections that sounds like tearing of the record, they are otherwise quiet and decent sounding.

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.

Another point is how many plays they will tolerate without significant deterioration. I do treat then with LAST so I may never know.
Interesting to compare original US Bitches Brew by Miles Davis and first release Japanese. Japanese vinyl is definitely quieter and EQ is better overall, at least for my taste, but Miles's trumpet has a little more power and presence in the US version. I listen to them both.