How does a record player needle read music out of just grooves (even when it's off and you spin the table by hand)?

sequoianoir

The power provides 2 basic functions. Firstly to spin the turntable and secondly to amplify the sound. The needle (stylus) when in contact with a groove of a record will still vibrate if the turntable is rotated. It may be rather quiet because the vibration is very small hence the need for an amplifier. Dec 21 02, 12:36 AM

greencavalier

I seem to remeber playing a record, many many years ago, with a dressmaking pin stuck throught the bottom of a hard plastic yoghurt pot (for amplification). Don't remember if we got caught though :-) Dec 21 02, 9:19 AM

sequoianoir

You can actually do it with a piece of paper. With a nice crisp sheet of A4 held at one corner, drop the diagonally opposite corner into the groove of a record spinning on a turntable. You'll hear its contents ! Dec 21 02, 11:34 AM

Gnomon

A sound wave is just a vibration in air. If you make a vibration in plastic that is the same shape, then rubbing a needle off it will cause the needle to vibrate in the same pattern. This will push the air and cause it to vibrate in the same shape again, so you have reconstructed your sound. Of course, the wave you get will be very quiet, so you must amplify it by some means. In early record players this was done by attaching a large cone to the needle. In later ones, it was done by electrical means. Dec 21 02, 11:33 PM