Gramophone Records and Players
Long before the introduction of mp3’s and CD’s most people used to play music through what are know as gramophone records, or just records. The most common of these records that were used from the 1950’s up to the early 1990’s was the Long-Playing record, known as the LP, which typically held an entire music album on it. Another popular form was known as the 45, which usually had two songs on it. The 78 was common before the 1950’s and usually had one song on each side, much like the 45.
So you may be wondering what all these numbers I am throwing around mean. It is the number of rotations per minute (rpm) that the record has while playing. For example, a 45 means it does 45 rpm’s while playing. Same for the 78. An LP does 33 and a third rotations per minute while playing.
These formats all use the same basic principle to make sound. A needle on a record player runs its way through the grooves of the record, which causes it to vibrate. These vibrations make the sounds that come out through the stereo. Records can be made in monophonic, stereophonic, and quadraphonic sound. With stereo and quadraphonic sound, the needle plays both sides of the groove, so two tracks of recording can be played at the same time.
The White Album by The Beatles with white vinyl
The way records are made is pretty straight forward. Most of the time when recording was done in the 60’s and 70’s, the actual studio recording was done on a master track, which is a really high quality magnetic 8 track tape recording. Think of a very large cassette that is extremely high quality. After that is made, the recording’s that the engineer wants to use, are played back and a cutting needle spins around on a record and record the vibrations into it. A stamp is made of the record and then it is pressed into the vinyl records, which are distributed.
An LP playing “Good Times, Bad Times” by Led Zeppelin
Records are all analog sound. This means it is the original sound that was recorded. It is constant sound the entire time. A CD or mp3 is digital sound. The difference is that a CD is snapshots of the original analog sound, put together to make the original sound. This means that the digital signal does not capture the whole sound wave. A record is therefor a truer sound then listening to a mp3 or CD. Many audiophiles (including me) prefer listening to records for this reason. Studies have been done that show the brain receives much more stimulation when listening to a record over a digital source.
The main problem with records is that they are much more susceptible to scratches and wear. Playing the record itself wears out the groove. So the sound quality deteriorates over time, where as a mp3 will sound the same no matter how many times you play it.
I really like vinyl, I am planning on doing my presentation on it this Friday. I have a pretty large collection, I am listening to my vinyl copy of “Let it Bleed” by the Rolling Stones right now. I find it so much more enjoyable than just surfing through iTunes. If you are interested in finding records just go over to Squirrel Hill, and go to Jerry’s Records. It is one of the largest collections of vinyl in the country.
Source:
http://www.howstuffworks.com/question487.htm
Milestones in Engineering History 
I thought your presentation was really interesting. I remember when my parents had a record collection when I was younger. What made you so interested in vinyl records?
I’ve always liked the old school music, be it rock, soul, or jazz. So that’s the medium most of it was printed on initially. Its just a cool hobby that I enjoy doing.
My roommate and also my dad are both really into vinyls, I’m usually very impressed with the sound quality that they have. My dad’s collection is quite old and still has doesn’t have too much trouble playing when he uses them.
It really depends on the conditions they were kept in and how many times they were played. I have some of my parents Beatles records that are so beat up just from the amount of times they were played. It is also bad to stack the records, which was common back in the 70s.