The Naked Scientists

The Naked Scientists Forum

Author Topic: How were vinyl records made?  (Read 5020 times)

Offline Karen W.

  • Naked Science Forum GOD!
  • *******
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
How were vinyl records made?
« on: 26/02/2009 08:37:38 »
Well I know this is old technology but I  am curious as to the procedures in making a vinyle recorded record. ((music)

What exactly goes into the medium that makes the record and also the technology involved in making the vocal print in the record itself..?

It all seems like a bit of magic to me!

Can someone tell me how this is done.... at my level please..... ;D :)
« Last Edit: 27/02/2009 08:19:46 by chris »


 

Offline BenV

  • Neilep Level Member
  • ******
  • Posts: 1503
    • View Profile
Re: How were vinyl records made?
« Reply #1 on: 26/02/2009 09:39:21 »
As to how they transcribe a waveform onto the disk, I'm not entirely sure - but one interesting thing is that the 'rate' of the music changes as you get closer to the centre of the disk - this is because the disk is turned at constant speed, so as you get closer to the centre, it takes less time to do one full rotation.  There's a good demonstration of it here:  http://www.thenakedscientists.com/HTML/content/interviews/interview/815/
 

Offline Don_1

  • Neilep Level Member
  • ******
  • Posts: 6890
  • Thanked: 7 times
  • A stupid comment for every occasion.
    • View Profile
    • Knight Light Haulage
Re: How were vinyl records made?
« Reply #2 on: 26/02/2009 10:14:42 »
As far as I know, sound waves picked up by a microphone are translated into vibrations which are etched into the sides of the groove on a master disc.

Take a look at this Karen, it explains how the vinyl disc is pressed.
Part 1
http://www.youtube.com/watch?v=xUGRRUecBik
Part 2
http://www.youtube.com/watch?v=IReDh9ec_rk&feature=related

There's quite some explanation on the actual recording methods here http://en.wikipedia.org/wiki/Gramophone_record
 

Offline Karen W.

  • Naked Science Forum GOD!
  • *******
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
Re: How were vinyl records made?
« Reply #3 on: 26/02/2009 10:48:06 »
As to how they transcribe a waveform onto the disk, I'm not entirely sure - but one interesting thing is that the 'rate' of the music changes as you get closer to the centre of the disk - this is because the disk is turned at constant speed, so as you get closer to the centre, it takes less time to do one full rotation.  There's a good demonstration of it here:  http://www.thenakedscientists.com/HTML/content/interviews/interview/815/

Thanks Ben..Lots of good information in there.

You know The part you wrote about the fact that the rings getting smaller as it reaches the center makes  it harder to understand..I get the difference in the speed of rotation being quicker because the size changes but I stiil am confused about how they make up for that....I will read it again...maybe I am missing something there.
 

Offline Karen W.

  • Naked Science Forum GOD!
  • *******
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
Re: How were vinyl records made?
« Reply #4 on: 26/02/2009 11:59:11 »
As far as I know, sound waves picked up by a microphone are translated into vibrations which are etched into the sides of the groove on a master disc.

Take a look at this Karen, it explains how the vinyl disc is pressed.
Part 1
http://www.youtube.com/watch?v=xUGRRUecBik
Part 2
http://www.youtube.com/watch?v=IReDh9ec_rk&feature=related

There's quite some explanation on the actual recording methods here http://en.wikipedia.org/wiki/Gramophone_record

Thanks Don.. very cool..I will watch them.. that sounds facinating.. do you tink there is a way one could make a home made  primative version that would work........to demo for kids how the voice is placed on..the record...?

I will watch the utube links tomorow..thank you so much!
 

Offline LeeE

  • Neilep Level Member
  • ******
  • Posts: 3382
    • View Profile
    • Spatial
Re: How were vinyl records made?
« Reply #5 on: 26/02/2009 16:18:02 »
As far as I know, sound waves picked up by a microphone are translated into vibrations which are etched into the sides of the groove on a master disc.

I thought I'd just add that the vibrations aren't etched in to the sides of the groove on the master; the groove, incorporating the signal is cut in to a blank master on a lathe.  The cutting head generally has two very powerful solenoids, angled to match the two sides of the groove, so that when the left and right signals are fed to them they cut the signals in to the appropriate side of the groove (in stereo disks).

The pitch of the grooves (although it's really just a single groove,of course), that is, how widely spaced they are, depends upon the maximum amplitude of the signal being cut; a signal with a very high amplitude results in greater movement of the cutting head, which in turn means that the grooves must be further apart to ensure that each groove doesn't interfere with the grooves either side of it.

There's a few pictures of a mastering lathe on this site, including some close-ups of the cutting head showing the angled coils (they seem to have screwed up the picture aspect ratio on some of the pics though)

http://www.soundsolutionmastering.com/index5.htm
 

Offline Don_1

  • Neilep Level Member
  • ******
  • Posts: 6890
  • Thanked: 7 times
  • A stupid comment for every occasion.
    • View Profile
    • Knight Light Haulage
Re: How were vinyl records made?
« Reply #6 on: 26/02/2009 16:51:05 »
Umm, yes, that's what I meant LeeE. My choice of words left something to be desired.
 

Offline Bored chemist

  • Neilep Level Member
  • ******
  • Posts: 8665
  • Thanked: 42 times
    • View Profile
Re: How were vinyl records made?
« Reply #7 on: 26/02/2009 18:26:10 »
As to how they transcribe a waveform onto the disk, I'm not entirely sure - but one interesting thing is that the 'rate' of the music changes as you get closer to the centre of the disk - this is because the disk is turned at constant speed, so as you get closer to the centre, it takes less time to do one full rotation.  There's a good demonstration of it here:  http://www.thenakedscientists.com/HTML/content/interviews/interview/815/

Thanks Ben..Lots of good information in there.

You know The part you wrote about the fact that the rings getting smaller as it reaches the center makes  it harder to understand..I get the difference in the speed of rotation being quicker because the size changes but I stiil am confused about how they make up for that....I will read it again...maybe I am missing something there.
You are confused because it doesn't make sense.
An LP record turns at 33 revolutions per minute and, whether the needle is near the edger or near the center, each turn takes the same time (1/33 min ie about 2 seconds).
What changes is the speed of the needle with respect to the record (which falls as the record plays).
 

Offline BenV

  • Neilep Level Member
  • ******
  • Posts: 1503
    • View Profile
Re: How were vinyl records made?
« Reply #8 on: 26/02/2009 18:28:59 »
As to how they transcribe a waveform onto the disk, I'm not entirely sure - but one interesting thing is that the 'rate' of the music changes as you get closer to the centre of the disk - this is because the disk is turned at constant speed, so as you get closer to the centre, it takes less time to do one full rotation.  There's a good demonstration of it here:  http://www.thenakedscientists.com/HTML/content/interviews/interview/815/

Thanks Ben..Lots of good information in there.

You know The part you wrote about the fact that the rings getting smaller as it reaches the center makes  it harder to understand..I get the difference in the speed of rotation being quicker because the size changes but I stiil am confused about how they make up for that....I will read it again...maybe I am missing something there.
You are confused because it doesn't make sense.
An LP record turns at 33 revolutions per minute and, whether the needle is near the edger or near the center, each turn takes the same time (1/33 min ie about 2 seconds).
What changes is the speed of the needle with respect to the record (which falls as the record plays).

Yes, sorry, I didn't really explain myself very well there.
 

lyner

  • Guest
Re: How were vinyl records made?
« Reply #9 on: 26/02/2009 18:48:18 »
The metal (aluminium, I think) master disc is /was  cut with a Lathe - a pair of strong electromagnets, mounted at 45degrees to the vertical, which move the cutting tool according to the left and right channels. This leaves a wavy groove which also varies in depth. The side to side movement carries the mono information and the vertical movement carries the stereo signal.
The disc goes round at a steady 33 1/3 rpm. This means that the system wastes some capacity. The inner turn of the groove needs to be cut at a suitable speed for reproduction and the outer turn is probably going about twice as fast as necessary.
Some early (78 rpm) disc systems had a variable speed (rpm) so that the cutting speed of the groove (m/s) was constant. This gave a bit more capacity. It was too fiddly, however, and required a more complex gramophone mechanism.

Interestingly, the 'early' 3 1/2 inch floppy disc drives (PC) used a constant speed but the Macintosh system varied the disc rotation speed and obtained a bit more capacity.
 

Offline LeeE

  • Neilep Level Member
  • ******
  • Posts: 3382
    • View Profile
    • Spatial
Re: How were vinyl records made?
« Reply #10 on: 27/02/2009 01:16:29 »
See CAV vs CLV
 

Offline Karen W.

  • Naked Science Forum GOD!
  • *******
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
Re: How were vinyl records made?
« Reply #11 on: 27/02/2009 08:11:20 »
As far as I know, sound waves picked up by a microphone are translated into vibrations which are etched into the sides of the groove on a master disc.

Take a look at this Karen, it explains how the vinyl disc is pressed.
Part 1
http://www.youtube.com/watch?v=xUGRRUecBik
Part 2
http://www.youtube.com/watch?v=IReDh9ec_rk&feature=related

There's quite some explanation on the actual recording methods here http://en.wikipedia.org/wiki/Gramophone_record

Don I just finished watching both of the Utube links ! So Cool! I* had no idea what went into making those records.. amazing.. I want to hang on to those Utube links.. great demonstration very cool! Thank you so much!
 

Offline Karen W.

  • Naked Science Forum GOD!
  • *******
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
Re: How were vinyl records made?
« Reply #12 on: 27/02/2009 08:14:35 »
As to how they transcribe a waveform onto the disk, I'm not entirely sure - but one interesting thing is that the 'rate' of the music changes as you get closer to the centre of the disk - this is because the disk is turned at constant speed, so as you get closer to the centre, it takes less time to do one full rotation.  There's a good demonstration of it here:  http://www.thenakedscientists.com/HTML/content/interviews/interview/815/

Thanks Ben..Lots of good information in there.

You know The part you wrote about the fact that the rings getting smaller as it reaches the center makes  it harder to understand..I get the difference in the speed of rotation being quicker because the size changes but I stiil am confused about how they make up for that....I will read it again...maybe I am missing something there.
You are confused because it doesn't make sense.
An LP record turns at 33 revolutions per minute and, whether the needle is near the edger or near the center, each turn takes the same time (1/33 min ie about 2 seconds).
What changes is the speed of the needle with respect to the record (which falls as the record plays).


Ok..I think I get that better...
 

Offline Karen W.

  • Naked Science Forum GOD!
  • *******
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
Re: How were vinyl records made?
« Reply #13 on: 27/02/2009 08:15:44 »
As to how they transcribe a waveform onto the disk, I'm not entirely sure - but one interesting thing is that the 'rate' of the music changes as you get closer to the centre of the disk - this is because the disk is turned at constant speed, so as you get closer to the centre, it takes less time to do one full rotation.  There's a good demonstration of it here:  http://www.thenakedscientists.com/HTML/content/interviews/interview/815/

Thanks Ben..Lots of good information in there.

You know The part you wrote about the fact that the rings getting smaller as it reaches the center makes  it harder to understand..I get the difference in the speed of rotation being quicker because the size changes but I stiil am confused about how they make up for that....I will read it again...maybe I am missing something there.
You are confused because it doesn't make sense.
An LP record turns at 33 revolutions per minute and, whether the needle is near the edger or near the center, each turn takes the same time (1/33 min ie about 2 seconds).
What changes is the speed of the needle with respect to the record (which falls as the record plays).

Yes, sorry, I didn't really explain myself very well there.

That's ok.. It takes me a bit and rereading sometimes many times before I get something... Thanks Ben!
 

The Naked Scientists Forum

Re: How were vinyl records made?
« Reply #13 on: 27/02/2009 08:15:44 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums