Vinyl composition effect on noise floor


So here's a curious thing I noticed today. Red vinyl is noisier than black! Ok, that's not true exactly, but check this out. I have a record that's half red, half black. I noticed after cueing up the record but before the music started that there was a distinct increase in the level of background noise when the stylus traveled into and through the red half, then a decrease when it went back to the black.

So, what would cause this? Because it's the same record, everything about the two halves must be the same... same master, same stamper, same pressing equipment, same packaging, same cleaning before I played it, same stylus in the groove, etc. Everything, that is, except the composition of the vinyl itself. Now, I know full well that color has nothing to do with it; I've got several very quiet colored discs and several noisy black ones. But I hadn't considered before that the makeup of the raw vinyl itself could be this important to a quiet background. Makes me want to get more info from pressing plants about how they source their vinyl. Thoughts?

Here's a video of the record spinning so you can see for yourself. Please excuse the poor quality, and turn up your speakers. http://vimeo.com/24946684
scissorfighter

Showing 1 response by tdaudio

I don’t avoid colored vinyl but I did not seek it out either. Of the 6 or 8 colored disks that I have I can’t make a case for or against.

I can remember some things from older posts but I decided to to do a little googling with some interesting stuff turning up.

Syntax posted; “In the black vinyl is more soot. This softens the vinyl and reduces noise in general. Promo-Copies for example have much more soot inside than normal pressings.”

Well the info I found is a little different. What makes records black is Carbon Black which in the following link is explained and is a little different than” soot”. This information indicates the addition of carbon black makes vinyl stronger as reinforcement in addition to coloring it black. Promotion copies may have more (or less?) carbon black than regular pressings, I don’t know. One thing I believe to be true is that promo copies are more carefully made during every step of the way and they may use only virgin vinyl.

The second Wikipedia link states that most vinyl records contain up to 30% recycled vinyl. This could be a big deal. I did not notice a definition of what recycled vinyl could mean.

The link for Carbon black is here; http://en.wikipedia.org/wiki/Carbon_black

The wiki link for info on records is here; http://en.wikipedia.org/wiki/Gramophone_record

Sorry, the second link has a lot of info on 78s and other stuff that does not pertain to this discussion.
One interesting thing I came across is that Classic Records is using and promoting clear (no carbon black) records. They claim that Carbon Black itself has magnetic properties that are detrimental to analog playback with a cartridge. It is covered in the lower part of this blog.
http://www.classicrecords.com/blog/

The Furutech demagnetizer is interesting, I think I have seen it discussed before but never gave it much thought. Great, another tweak!

Two things I like about black vinyl is how it looks - which may be the biggest reason for the use of Carbon Black – and I like that I can see dust if its there.
Hope that helps. Terry