Difference between micro line and gyger s stylus

The "donut" 45's I'm referring to were mainly made in the 80's. They were more like hard plastic than soft vinyl. RCA, A&M, Columbia/epic/CBS, Casablanca, and a few other labels used it. The needle would litteraly tear up the record as it played. You could lift the tone arm up and see the build up of gunk on the stylus and white residue on the 45. Different cartridges would damage them while others would not.

Thank you, Arnold. AFAIR, the styrene records that I handled were from an earlier time than yours, so it is good to know that there are more labels and time periods to watch out for. FWIW, I believe that molded styrene was used to save production costs.

I wonder if there is a URL which discusses these styrene records at length (labels, time periods, artists etc.) It would also be interesting to know if all styrene records behave in pretty much the same manner (regardless of production era or label), or some can better withstand a small side-radius stylus than others.

Records turning white as they are played is not a pretty sight!

regards, jonathan carr

Hi Jcarr,

I found some information about styrene and issues with shredding them and which types of carts do not and the stylus they use:

http://www.stevehoffman.tv/forums/archive/index.php/t-80334-p-4.html

A-L

To add more info: the best cart I had owned in the past that played styrene without any damage was the shure V15Vxmr and that uses a microridge stylus.

Arnold, very interesting! In my experiments, changing the stylus from a small side radius (including an microridge) to a larger one kept styrene records from being chewed up. Other parameters were kept the same, so I have fair confidence that the size of the side radius is a core factor.

And yet there are individuals like yourself who report being able to play styrene records with microridge stylii and get no damage. 'Tis a mystery.

The V15VxMR had low vertical tracking force requirements, so that could be one factor.

Also, if you look at the second table here http://www.shure.com/proaudio/products/djphonocartridgesandneedles/ssLINK/us_pro_djlibrary_phonograph

you can see that while the 3.0mil front radius computes to 75um (which is per Namiki's design), the side radius of 0.15 computes to 3.75 (larger than Namiki's original design specifications of 2.5um).

It could be that Shure uses a variant of the MR modified to have a larger side radius.

regards, jonathan carr