How Vinyl Works - just for fun

andrushkiwt

Well-known member
This isn't anything really pertinent other than my own interest being piqued here. I have always wondered exactly how a record player captures and produces the sound in the grooves of the vinyl. Of course, I have watched dozens of videos and read plenty of articles, but there is one aspect that has never been properly explained to me. Let me tell you what I understand and where I am having a hard time grasping the concept, before we get many replies that aren't helpful to my understanding.

Sound is produced. That sound vibrates a needle. The needle cuts small grooves into vinyl. When traced over again, with a certain device, and into an amplifier, those grooves play back the recorded sound. So, then, the recorded sound is literally etched into the vinyl.

Here's what I don't understand fully enough - Surely those grooves can be reproduced with things OTHER than sound. The vinyl doesn't know that sound caused the needle to etch into it, only that it is etched. So, couldn't we take a needle in hand and introduce small grooves into the vinyl to reproduce the same sounds? What is it about vibrations from sound moving the needle and making grooves that is distinct from a human holding the needle (or a machine, even, for preciseness) and replicating the same grooves? The vinyl wouldn't know what caused the grooves, only that they exist. How does a groove that is, let's say, .1mm thick and bends at such angle for so long, and is X mm wide, etc. etc. produce ONLY that sound that it does? What if no sound was produced but the EXACT same groove the needle made from sound was produced by hand or machine? The groove would be no different, yeah? So why would the played back sound be different?

Hopefully where I am misunderstanding was made clear. Obviously, the thing works. lol. I'm just confused on this one aspect and I've never looked into it beyond a few videos which never closed the knowledge gap. Thanks anyone
 
I think you're exactly right taras, it's just a track and the record doesn't care what made it. You could probably draw any sound you want by cutting it just right. Or maybe even store video if you translated the pictures to vibrations, and back again, I wonder!
 
Really though, if I made a machine that etched grooves into vinyl in the exact same way the grooves are on a, let's say, Mozart record...would it sound like Mozart? Same grooves. Same depth and thickness to them, just made by machine/hand instead of vibrations from sound. On a microscopic level, those grooves must be incredibly detailed and precise.

Haha, looks like I'm only hundred+ years late to the party!
 
Truth of the matter is, sound has never cut vinyl. At least not as far as I know. The first sound recorders were wax rolls. Sound would be captured causing the needle to move and cut a groove in the wax roll. Flubbed up and want to start over? Heat the wax so it reflows. The source of a signal for vinyl comes from a tape recorder. So, if you had moxart on tape, you could reproduce it on vinyl. Will it be exactly the same? Nope. Limitations of the tape, the amplifiers, the cutting needle, vinyl, scratches, dust, warpage, etc... all will alter the sound. But, it will be close enough so you can listen and say, Hey, that's Mozart!

Detailed and precise is a relative term. I work in the microscopic world and vinyl records would not come to mind as being detailed and precise. :D
 
The first sound recorders were wax rolls. Sound would be captured causing the needle to move and cut a groove in the wax roll.

...and if you put the exact same grooves into the wax via some other method, hand perhaps, you would reproduce the exact same sounds?
 
If the grooves were cut EXACTLY the same, then sure. But....

I guess that's what I have a hard time believing and acknowledging. How does a groove in wax sound like a church/hall/outdoors, etc... it's a damn groove! lol. science.
 
Someone should type out the binary data for a CD from start to finish. It's just a bunch of ones a zeros. How hard could it be?
 
It's data. It represents voltages that move the speaker cone. You could interpret the data in any other way and display it as text or colours, depending what you decide the depth of the groove (and the associated numerical value) means.
 
Ya, it can be done, but the hand scratch would be more of a painting thing. Those who scribe the Bible on the back of a postage stamp might have a head start
 
If you've seen a wave form displayed on your computer screen, then that's a pretty good approximation of what a groove looks like when magnified
 
Someone should type out the binary data for a CD from start to finish. It's just a bunch of ones a zeros. How hard could it be?

Green Day album, circa 1993:

0100111

Green Day album, circa 2012:

10000000000000111010110001111111110101000000000011010011100101010000000000111000000000111100100000111111100000000001101110101001011000000000000000111111111111110000000111000000000000000111111111111000010101010100000000011010000000110110011111111111100101000001101100000000011010101000000000010110110101001111111111111111100000000000000
 
Late 1970s/early 1980s electronics magazines would sometimes have flexi-disks containing computer software. Though technically this was still audio since it was using FSK encoding or similar.

As for video, Baird managed to record TV signals for his 30-line system on shellac.

However, you might find this interesting:
https://www.youtube.com/watch?v=fCWLaAwr3sM
 
Many of the early home/toy computers used the audio cassette format. Modulation is modulation
 
Or maybe even store video if you translated the pictures to vibrations, and back again, I wonder!

Only VERY low resolution video. Even high quality audio only needs the track to vibrate 20,000 times per second. Video gets you up into the millions which would need a very tiny needle or a very big disc turning very fast.

...which reminds me of an 11 year old Bobbsy who thought he'd invented a video recorder when he plugged the TV antenna into the mic input of my dad's reel to reel. I was very disappointed when hooking the speaker output to the antenna in of the TV didn't give me pictures.
 
Only VERY low resolution video. Even high quality audio only needs the track to vibrate 20,000 times per second. Video gets you up into the millions which would need a very tiny needle or a very big disc turning very fast.

...which reminds me of an 11 year old Bobbsy who thought he'd invented a video recorder when he plugged the TV antenna into the mic input of my dad's reel to reel. I was very disappointed when hooking the speaker output to the antenna in of the TV didn't give me pictures.

There was a camcorder system that used audio cassettes. Needless to say, the video quality was bad. Though apparently they have a niche following for people who are into lo-fi video as a special effect.

As for the videodisks, what they tended to do was use capacitance instead of the stylus vibrations - the grooves were mostly to keep the stylus tracking the data correctly.
 
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