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echinopsis
Apr 13, 2004

by Fluffdaddy
The pits and lands do not directly represent the 0s and 1s of binary data. Instead, non-return-to-zero, inverted encoding is used: a change from either pit to land or land to pit indicates a 1, while no change indicates a series of 0s. There must be at least two, and no more than ten 0s between each 1, which is defined by the length of the pit. This, in turn, is decoded by reversing the eight-to-fourteen modulation used in mastering the disc, and then reversing the cross-interleaved Reed–Solomon coding, finally revealing the raw data stored on the disc. These encoding techniques (defined in the Red Book) were originally designed for CD Digital Audio, but they later became a standard for almost all CD formats (such as CD-ROM).
c



cool

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Bluemillion
Aug 18, 2008

I got your dispensers
right here

Got his rear end.

Internet Old One
Dec 6, 2021

Coke Adds Life

graph posted:

are audiophile morons still paying $$$ for gen 1 ps1s

Is the PS1 DAC actually any better than other Sony DACs?

Aren’t Sony CD DACs just good in general?

mystes
May 31, 2006

echinopsis posted:

am I remember correctly that there were multiple kinds of RW cds that weren’t compatible
Aren't you thinking of DVD-RW and DVD+RW?

echinopsis
Apr 13, 2004

by Fluffdaddy
yes who isn’t rn

Silver Alicorn
Mar 30, 2008

𝓪 𝓻𝓮𝓭 𝓹𝓪𝓷𝓭𝓪 𝓲𝓼 𝓪 𝓬𝓾𝓻𝓲𝓸𝓾𝓼 𝓼𝓸𝓻𝓽 𝓸𝓯 𝓬𝓻𝓮𝓪𝓽𝓾𝓻𝓮
don't forget DVD-RAM

lampey
Mar 27, 2012

you can mail a cd for $1.08 in the US as a letter in a cardboard sleeve

echinopsis
Apr 13, 2004

by Fluffdaddy
is there a formal difference between disc and disk



my mum used to call my 3.5” floppies “tapes” and tbh they are just a big flat round tape

cds are not tapes tho

echinopsis
Apr 13, 2004

by Fluffdaddy
cds are great tho

like they worked out how high frequency we can hear. doubled it for ny good reason

and 16 bits.. it’s a sufficient number of bits


like, back in fuckin rotors day they nailed it

from a practical point of view cd audio is about as good as it can get




on vinyl did they ever do parallel tracks? like imagine if you let the record play and it played some track but if you put the needle there you could sometimes get a different track?



also remember when cds could store track names ? cool



imo they should do a retro cd player and you put the cd upside down and the laser instead of being on a screw it’s on a swing arm like vinyl. now that would be sick



playstation cds we’re black. is that how it knew they were legit

polyester concept
Mar 29, 2017

disc is optical and disk is magnetic

mystes
May 31, 2006

polyester concept posted:

disc is optical and disk is magnetic
oh yeah? and what if it's floptical?

echinopsis
Apr 13, 2004

by Fluffdaddy

polyester concept posted:

disc is optical and disk is magnetic

what about vinyl co that’s neithe



hang on Im looking this up and seems like you’re making it up

echinopsis
Apr 13, 2004

by Fluffdaddy
herniated disc or disk?

depends if magnetic or optical

Visions of Valerie
Jun 18, 2023

Come this autumn, we'll be miles away...

lampey posted:

you can mail a cd for $1.08 in the US as a letter in a cardboard sleeve

fond memories of ordering niche music from europe and just an envelope would arrive, with a cd and booklet, sans jewel case. Think I still have a pile of empty jewel cases somewhere for this reason

Brexit the Frog
Aug 22, 2013

echinopsis posted:

on vinyl did they ever do parallel tracks? like imagine if you let the record play and it played some track but if you put the needle there you could sometimes get a different track?

there was a "three sided" monty python record that did this. and some other examples iirc

Skinnymansbeerbelly
Apr 1, 2010
smdh that no one has mentioned pre-gap audio itt

echinopsis
Apr 13, 2004

by Fluffdaddy
now that’s the kind of poo poo that I love

The Management
Jan 2, 2010

sup, bitch?

echinopsis posted:

with cd rom did that have much more redundancy and whatever compared to the phonograph nature of audio cd

CD ROM dedicated 256 bytes out of every block (2304 bytes) to error correction data. the cross-interleaved reed-solomon encoding ECC made them very resilient to clustered errors. this means that they are very good at recovering from errors caused scratches on the disc surface, even if the scratch is parallel to the track path.

The Management
Jan 2, 2010

sup, bitch?

echinopsis posted:

cds are great tho

like they worked out how high frequency we can hear. doubled it for ny good reason

and 16 bits.. it’s a sufficient number of bits

they doubled it for a very precise reason, the Nyquist–Shannon sampling theorem, which is a fundamental rule of digital sampling. it basically says you can perfectly encode any analog signal if you sample it at twice the maximum frequency.

The Management
Jan 2, 2010

sup, bitch?

Internet Old One posted:

Aren’t Sony CD DACs just good in general?

no, they suck

Sweevo
Nov 8, 2007

i sometimes throw cables away

i mean straight into the bin without spending 10+ years in the box of might-come-in-handy-someday first

im a fucking monster

gotta colour in the edges of the CD with your special green marker pen

Dans Macabre
Apr 24, 2004


post hole digger posted:

how about you cds nuts then :w00t: :rowdytrout: :blastu: :cawg: :woot: :troll:

Silver Alicorn
Mar 30, 2008

𝓪 𝓻𝓮𝓭 𝓹𝓪𝓷𝓭𝓪 𝓲𝓼 𝓪 𝓬𝓾𝓻𝓲𝓸𝓾𝓼 𝓼𝓸𝓻𝓽 𝓸𝓯 𝓬𝓻𝓮𝓪𝓽𝓾𝓻𝓮

Sweevo posted:

gotta colour in the edges of the CD with your special green marker pen

color them in?? I’m using a $$$$ tool to shave them off at a specific angle

Sweevo
Nov 8, 2007

i sometimes throw cables away

i mean straight into the bin without spending 10+ years in the box of might-come-in-handy-someday first

im a fucking monster

also did you know you can hang a CD from your rear-view mirror and it dazzles speed cameras

echinopsis
Apr 13, 2004

by Fluffdaddy

The Management posted:

CD ROM dedicated 256 bytes out of every block (2304 bytes) to error correction data. the cross-interleaved reed-solomon encoding ECC made them very resilient to clustered errors. this means that they are very good at recovering from errors caused scratches on the disc surface, even if the scratch is parallel to the track path.

seems like back in the day when data space was more scarce they made all sorts of good engineering decisions

The Management posted:

they doubled it for a very precise reason, the Nyquist–Shannon sampling theorem, which is a fundamental rule of digital sampling. it basically says you can perfectly encode any analog signal if you sample it at twice the maximum frequency.

I slipped a wee typo into my post on purpose ;)

Dans Macabre
Apr 24, 2004


graph where’s best place to buy needles / cartridges these days I asked in the vinyl thread and they didn’t answer

graph
Nov 22, 2006

aaag peanuts

Dans Macabre posted:

graph where’s best place to buy needles / cartridges these days I asked in the vinyl thread and they didn’t answer

if you know what you want, whoever has the best price ?

Dans Macabre
Apr 24, 2004


graph posted:

if you know what you want, whoever has the best price ?

Well I wanted shures but they don't make those anymore?

I guess I want ortofons then :/

graph
Nov 22, 2006

aaag peanuts

Dans Macabre posted:

I guess I want ortofons then :/

should have wanted orts to begin with :smug:

graph
Nov 22, 2006

aaag peanuts
best sounding combo i ever heard was a niteclub nana with an elektro tip

Dans Macabre
Apr 24, 2004


I'm sure I will be able to tell the difference on my $20 headphones

graph
Nov 22, 2006

aaag peanuts

Dans Macabre posted:

I'm sure I will be able to tell the difference on my $20 headphones

lol if you're still not using v700s

SlapActionJackson
Jul 27, 2006

Internet Old One posted:

You sound smart. What was meant by the “8 times oversampling” that my cd player was so proud of itself for?

Basically, it is difficult, and therefore expensive, to build a 16bit wide DAC with accurate voltage resolution using standard ASIC design and manufacturing techniques. It is very easy, otoh, to build one with very accurate temporal resolution. Fortunately, the math of digital signal processing lets you trade one for the other, losslessly. So once it became practical to put enough processing power in consumer CD players, manufacturers used DACs with smaller word sizes at a higher frequency. 8x oversampling means they convert the 44.1khz samples to 352.8 kHz, and run it through probably a 4 bit DAC.

You can take this to the extreme and go all the way to a 1 bit DAC, which is trivial to construct, but requires ~256x oversampling. And in the right era, you did indeed see both of those claims used in the marketing of CD players.

George
Nov 27, 2004

No love for your made-up things.
i use cds because im tired of todays hyper-digital fast paced life and try to use old analog formats whenever possible

fart simpson
Jul 2, 2005

DEATH TO AMERICA
:xickos:

George posted:

i use cds because im tired of todays hyper-digital fast paced life and try to use old analog formats whenever possible

agreed

echinopsis
Apr 13, 2004

by Fluffdaddy
cd is the analog of digital

Farmer Crack-Ass
Jan 2, 2001

this is me posting irl

graph posted:

lol if you're still not using v700s

i'm still using a set of mdr-v6 headphones i bought off a goon twenty years ago

fart simpson
Jul 2, 2005

DEATH TO AMERICA
:xickos:

echinopsis posted:

cd is the analog of digital

correct

ADINSX
Sep 9, 2003

Wanna run with my crew huh? Rule cyberspace and crunch numbers like I do?

I don't have anything to add but want to say this is a good thread and I'm enjoying it, looking forward to some more facts about CDs

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echinopsis
Apr 13, 2004

by Fluffdaddy
the thing that seems very cool about cds is they seem a bit “hackable”, like people learned to abuse them a bit, for example tracks before track 1, you could only access by rewinding and some players couldn’t do it

and the management basically letting us know that they really are the analog of digital. a big gently caress off wav file

remember when cd players became capable of reading mp3 off of cd rom? that was cool in a way but I prefer knowing the cd player is doing gently caress all computing

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