Edison's chance happening upon the 'needle' was thus : while trying to improve the speed at which a telegraph message could be transmitted, he had a small needle prick his finger with a change in signal ampitude. Edison thought to transcribe this to paper, and then to tinfoil, which was resilient enough to enable playback (paper tended to tear.) Finally this evolved into his wax tubes, after some flirtation with tinfoil. The signal from these wax tubes were then amplified by a horn, or the listener would put on little earpieces connected to the needle. Look to the left and you will view some of the grooves scribed on a real piece of Edison tin foil!

The early record players weren't amplified. They simply had a needle reading the record, either reading the sound wave as hills and valleys (y variation) or 'back and forth' motion (x variation). Technically these 'needles' are transducers : a device used to translate energy of one type to energy in a new medium. This needle, vibrated by the grooves, was connected to a thin diaphragm in the hollow tonearm, which then vibrated the air and was amplified by a big fat horn. This horn sometimes was sitting right on top of the tonearm, meaning that the record had to actually pull against it... a heinous concept to any modern dj. Back then that was how small turntables were made, eventually however, as Victrola's turntables got more intense they fixed the horn and pivoted the tonearm from the horn. These early 'pure analog' systems are an example of mechanical to acoustic energy, and technically required no electricity to run (although unless you had perfect 'cranking' hands you would get something with insane tremelo) Still, this crude amplification was not an effective way of playing recorded music for a mass (or noisy) audiences, and soon the "modern" needle would be upon us.

The modern records and record players are highly specialized to keep sound to a premium while keeping wear on the record to a minimum.The needle works like the early ones did - a small polished diamond or sapphire slides along the record groove and 'reads' the sound recorded in there.These vibrations travel up the needle into the cartidge, where the vibrations move a small magnet. This magnet is surrounded by 2-4 other magnets, and when the stylus-magnet is moved a small current is induced, which is then sent out to an pair of RCA cables. The signal from these magnets are quite weak, however, so it is then necessary to run the signal through a proper turntable pre-amp before sending THAT signal out to your speakers, headphones, etcetera. This is why a turntable will sound incredibly weak if you just run it into a "line/cd in." This method of amplification greatly reduces wear on the record as the stylus does not need to dig so heavily into the groove, compared to the ... audible output of the early grampahones, the sound produced directly from this vinyl-to-diamond apparatus is barely audible. As technology in stylii progressed a "moving coil" variant of the same notion was developed, for the purposes of lesser wear on the record and a more accurate translation of groove-to-sound. The trick is that typically the moving-coil type stylii need an even better pre-amp than the moving magnet, and can often be more expensive than the moving magnet. The very top-end moving coil cartridges are... "not suited for mass production. Each of the four coils contains between 11 an 24 turns of wire, depending on model, and has to be wound by hand under a microscope. The wire itself is much thinner than a human hair." (http://www.ortofon.com/)

There are two types of modern stylus, elliptical and spherical. These designations refer to the tips of the stylus - there is no actual "rolling" of a small ball-point. Both have their own merits - elliptical stylii wear on the record less, spherical tips track much more accurately and are more resistant to scratches in the record.