Assuming proper setup and adjustments as warranted, and appropriate care taken what is the validity of the statement in the article that stylus need to be replaced around 500 hours within the context of high end cartridges? Depending upon one's listening habits the 500 hours suggests a year or less of use and an expensive replacement proposition.
I think you mean to ask if the claim is true rather than if the claim is valid. No argument is given for the claim against which validity could be assessed -- other than some vague notion of friction and things wearing out over time.
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Intuitively, it makes sense that vinyl records degrade ever so slightly as you listen to them. The stylus on a turntable is made out of diamond or sapphire, and scrapes along a comparatively soft PVC plastic. That scraping creates friction and heat that dislodges PVC material at a microscopic level. For reference, the needle itself wears out and requires replacement after as little as 500 hours of playing time, so imagine how the PVC is feeling after being played even just a few dozen times. Especially where it concerns those delicate details like high frequencies."
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https://www.slashgear.com/1599756/do-vinyl-records-actually-sound-better-than-cds/
Cartridges can be re-tipped to acquire a fresh stylus instead of throwing away the entire cartridge. Cost varies.
So we can do it this way ...
Q: Is it true that stylii have a 500 hour life span?
A: Hard to say but as a generalization for all cartridges, false.
Stylus lifespan depends on many factors and variables, a few of which are: stylus shape, stylus composition (typically diamond), stylus quality, vertical tracking force, condition on the vinyl record surface, frequency of stylus care/cleaning.
Then there is the question of what counts as wear sufficient to declare a stylus tip worn out?
Numerous individuals and some companies have done studies on the topic of stylus wear. For example, Shure's advice from 1978 on lifespan is all over the map and also it has evolved over time. You will find 500 hours, 500 to 800 hours, 600 to 800 hours, 800 to 1,000 hours, and 500 to 1,000 hours (
pdf). Jonathan Carr of Lyra cartridge manufacturey said you should get 3000 hours from an Ogara PA stylus shape, Namiki Microline shape a bit less (
ref). Mike Bodell's
article is a great source. There is a long
thread on the Hoffman site that covers the topic.
Fwiw, imo, the OP's article is fraught with so much misinformation that it discredits its publisher. Members of the digerati looking for clickbait or diss on analog should find higher quality information to serve them better.