Nagging Vinyl Record Question - How Do I Tell If It's A Scratch Or Dirt

Many people believe their vinyl records are "scratched" beyond repair when in fact the problem is deeply ground-in material (dust and mold etc) stuck to the inside of the record's grooves. You can tell the difference between scratches and various forms of gunk stuck in the grooves by asking; does the sound happen once a revolution of the turntable, or do I hear pops and crackles for the whole records revolution? If you hear pops and crackles all the way round, it is more than likely deeply ground-in material that is stuck inside the record grooves.

Here's how it happens. Small particles of mold, dust, oils, skin, smoke and other material actually get stuck to microscopic ridges located within the grooves of the record. This is caused by the friction of the stylus passing over the tiny ridges and generating just enough heat to make the tiny ridges sticky. The stylus then picks up loose material as it travels through the grooves and deposits them on the sticky ridges where they are there to stay. 

There are many fluids and cleaners on the market, ranging from between a few dollars and several hundred dollars. Using one of those products to clean your vinyl before each play will go a long way towards cutting down on that dust and dirt. Though much to an audiophile's chagrin, it's impossible to get the vinyl completely clean and dust free. That is, unless you can play it in a "clean room"