[nathanm]

Okay, so I was never a psyhics major but I've seen on numerous occasions the description of a record needle putting TONS of force on the vinyl surface and generating all sorts of nasty melting heat.  Ummm...I thought the tracking force was like 2 grams!?  How do they get "tons" out of this scenario?  I'm not quite clear on how a featherweight little piece of metal gliding across the record surface is exerting that much weight.  If it was I would imagine it would not only dig a hole straight through the vinyl but also snap your platter in two and the rack as well!  Confusing...

[bubba966]

I would imagine that the "tons of pressure" comes from the fact that if you measured the pressure the needle was exerting compared to the area of contact and used a measurement such as PSI, that it would equate to tons per square inch.

'course my edjumacations didn't get past high school, so I's only guessin...

[michael w]

Hi nathan,

Bubba is spot on.

Although the tracking force is "only" 2g, this force is concerntrated on a tiny spot in the record groove through a stylus usually only 0.5 to maybe 1 millimeter in diameter.

Pressure measured at this point is literally measured in tons per square inch.

As for the heat question, the stylus moves through the record groove so fast that the heat doesn't get to build up in one spot so the vinyl has a chance to recover, many audiophiles reckon you should allow a record to rest for an hour or two before playing the same track again.


A really good source for answering all manner of audio questions like this is the book:

Good Sound by Laura Dearborn
Sub-titled "An uncomplicated guide to choosing and using audio equipment", and written in easy to read English with a minimum of techno-gobblety-gook, it provides all the basics that you need to know about hi-fi.

I think the book is now out of print but any good library should have a copy.


cheerio