CDs: More to Talk About (Sony vs. Philips)

CDs: More to Talk About (Sony vs. Philips)

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Where's the comparison, between the philips and sony tracking, mechanisms, or did I miss that did, I miss it or did you forget to explain the Sony solution, for keeping the laser on track and in focus, how does sony do the tracking the, rest of that comment was really insightful thanks for sharing okay, could I have been a little more clear I'll show you a Sony system later on but if you didn't see my last thing yes, yes, I could have but, this is in fact later on so, perhaps maybe we shouldn't jump to conclusions so quickly tell. You what I'll work on being a little more precise in my choice of words and perhaps you, dear viewer could, refrain from jumping to conclusions, quite, so quickly if we put our minds to it together we can enhance our understandings, through complex, thought both on the part of the speaker and on. The part of the listener and. Alright. This video is coming at you in three parts as we discussed in the last video no wait wait wait, the, ding was way too loud let's tone it down much. Better so. As we discussed in the last video we're, going to take a look at some of the waveforms, coming from the components, of this Magnavox, which is really a rebadged, Phillips, because Phillips couldn't use that name in the US due to its passing similarity to Philco I guess but that's a stretch CD, player that, will be part 1 in, part 2 we'll take a look at a Sony laser pickup and discuss the differences plus, I will tear this one apart to expose the laser diode and photo diodes and in, part 3 we'll discuss why Sony's pickup solution would become the default standard used, to this day and optical drives we'll begin with part 1 and part, 1 will be quite a bit different from most other videos that's, because much of it is unscripted. Off-the-cuff. Just, gonna wing it yeah. But first a few Corrections, as usual, the Internet has provided answers, that I did not find and has revealed some mistakes and false assumptions, from the last video of course. But, that's ok we all make mistakes and, now I'm gonna tell you what we learned thanks to the diligent research of more knowledgeable, people than me remember. It's ok to not know everything and it's, ok to ask for advice from professionals, and that's, let me reveal the most dumb mistake, and it was right on screen the, best, kind of mistake, I had. Been assuming that pin 10 was the output signal from the focus chip and that it, would be a binary stream, from the pits and land boy, was that wrong on many counts first, it's not pin ten that does that it's pin three then it's labeled right here on the datasheet pin. Three is also labeled to decoder which I missed and most. Importantly, it's a sum of the outputs from hall for photo diodes as illustrated, right, here yes, pin 10 also gets the sum of the four diodes but unlike pin 10 pin 3 has an amplifier, equalizer and another amplifier to boost the output. Mm-hmm. I want to give a big thanks and shout out to Zim 0 2 5 6 who not only created the helpful, diagram, that I used on a few occasions but, who also gave more complete info on what is going on the.

Motorola Processor, is a custom, chip based around an H c08, microcontroller. And it is in fact the decoder, that is doing most of the work I couldn't, find its datasheet because the P on the end was limiting my search results, and, to think we just learned about minding, our P's and Q's anyway, in fact the decoder is handling all the raw data undoing, the 8 to 14 modulation, isolating, the sub code and all that it even, digitizes, the output from pin 3 which at this point is still analog, which we'll see in a moment it, sends the extracted, sub code to the processor. So it knows how to handle the disk and respond to user requests, really. The processor, is just managing the living and breathing tasks, of the machine such, as the user interface, display, and other goodies like popping, the disc tray in and out and getting the whole process going speaking of the disc tray a few people had asked how the machine can tell that the disc tray has been pushed in manually, as opposed, to someone hitting the open closed button some. Other people noticed this strange button, switch near the decoder these. Two groups of people are discussing the same thing to. The right of the disk tray is a little series of levers that rest on top of this button when it's assembled little. Nubs on the bottom of the tray will cause this to push down on the button in either the open or closed position this. Not only tells the processor, that the tray has reached the end of its travel in either direction but it also means that it can detect if the tray has been pushed in as, the button will be released and lest the switch open as soon as the tray is moved out of its open position okay, it's time for this script to be put to the side I've got a sort of odd setup here because I need to see both the oscilloscope screen and what I'm poking on the board so we're going to do some picture and picture editing, magic and throw the scope screen up hi, excellent. And you know what maybe we'll throw another camera, up here somewhere so that you can see what I'm doing even, better all of the cameras, all the tripods, while, this is awkward. They. Don't have to do as. Promised, we're gonna poke around on some of the things here now I brought my laptop here so I can actually go and look and see what I'm looking at and you'll, notice these uh wires. That, I've soldered on to chips underneath I'll bring. Up the image of that part, of the issue with this player is that it has to be the. Ribbon, cable between the drive, and the board is very very short and there's, pretty much no way to operate, this unless. It's assembled I really, don't know how people would service these things because it you know a lot, of the a lot, of the stuff. That I want to see is underneath, the CD reader like the the. Tracking and focus chips are basically directly under here that's. Not helpful, but, we could see what else we can take. A look at I did. Find, just, from poking, at one point I found me. The. Raw data stream, I think, it was one of these guys, unfortunately. What, is happening, here Oh. Well, this is kind of interesting what's, I wonder what's on this line let's see if I can figure it out notice. That we're. We're. On a really long time scale I think. This is the sub code if, I can hopefully, get, the triggered. I'm. I'm. Really, I have no experience with a scope so just just, so you know. Let's. Try. Oops. That's what I meant that's what I meant the other way oh it's. Probably you okay. Yep. Okay I found. It so, this, here, is the waveform that's, coming from the.

Amplifier. Chip from me art from the. TDA 808. II I want, that one so, this this, is the amplified. Output of. The. Oops. Of the, pits and land so this is the raw analog, signal, coming from the disk, and if. We look a little closer you. Can. See if I touch the disc, see. How that's, well. I've killed it, great. Great. Job so, if I kind of just touch it you can see the it. Slows down a bit now. You zoom out a bit OOP zoom, out a bit. See. That. Just. Completely it, gave up their that, click sound you heard I believe, is the laser, kicking. Up all the way. But. Yeah so this this, isn't the raw output from the photodiodes but this is the amplified, output coming from pin three going. To the, decoder the, output from the photodiodes is. Very. Very small, this is, and. Take a look compared in the voltage level there's almost nothing there and. It's so noisy I can't see anything these. All should be. The. Same. There's. Nothing, there. Which. Is a shame because I really wanted to show you that oh. Well. I. Wanted. To show you some interesting stuff and I think that we saw some interesting things but. Not. As many as I was hoping well. With that disappointing, segment out of the way let's move on to the part that I didn't forget about to. See how Sony handled, the optical system differently we, need to get our hands on a Sony CD player hopefully, of similar vintage to this Philips one opor. Fect a Sony CD changer, from 1992. Now. It doesn't really matter that it's a changer there's still a standard, CD mechanism, in here it's just on the pivot and will happily pop up and fall down to greet or say farewell to the disc hit plays it. Works in tandem with the disc tray which rather than just being in any Audi operation. It's an inny Audi with rotational, flair now, I embarked, on the frightening task of getting this mechanism out of this player armed. Only with an ordinary screwdriver, I went ham-fisted and, started unscrewing, stuff, before. I realized I hadn't, filmed the close-up segments, of the laser tracking, a disc, after. Undoing, what I had begun I began once more the, screws are the enemy be gone or, be, twisted counterclockwise sufficiently, until such time that they can be gone having. Gained unrestricted, access to our prize I loosened, at the forest bruise holding it in place but, it wouldn't budge, yet, more screws needed liberation, until finally, I had successfully, removed the crown jewel from the temple of forbidden. Technology, and here. It is one, of the big differences you'll see between this and the Phil mechanism, is everything. Is much more integrated, in fact. This one chip here if the datasheet I found is it all correct link below has, 32, K of RAM built-in does, the e FM demodulation as, well as the circ error correction, handles, the focus tracking and spindle motor using, this chip as a driver to handle the power extracts. The sub code provides, a data output for the DAC and can even do such exotic things as double speed playback and variable, pitch playback, assuming, the player it's inside has those functions enabled did, I mention its bilingual, it's interesting how just four, years time managed, to integrate functions, that are spread out via multiple, chips on this Philips machine into, just this one chip on the board of the laser pickup but, that makes a lot of sense see this Philips board only works with one mechanism because. It's driver components, are part of the mainboard design anything. But if philips cdm-t. Some. Modification. But, for the sony machine this, ribbon cable is essentially, just providing a power ground, a communication, bus to the cpu and a data stream for the DAC this. Component, can be completely. Redesigned, and so long as it accepts, the same inputs and produces the same outputs the mainboard really, won't care this. Allows Sony to make production improvements, and even radical changes, to this mechanism and how it works without disturbing, the mainboard you can see how Sony played a modular, approach via the markings on the board this, one board was used in many different players with different components marked, Forex player only by. My count it was used in at least five players really. Sony's, markings, are just a lot more helpful wondering. Which one of these is the DAC Hey look it's labeled right here and you'll, find a pulse chip on the bottom I'm, pretty sure these are one bit Dax based on some vague research I'm sure someone will correct me if I'm wrong and I'm counting on it and the, fact that they've labeled these jumper, connections, on the top of the board for what, they are sure is helpful that.

Would Have been nice, Philips anyway. Back to the laser because that's the real difference first. Gone is the swingarm instead. The laser is mounted on a sled which moves linearly, with, the help of this rack and pinion drive now. You might suspect that this drive arrangement, does not have the precision to track the disc the, floating arm of the Philip system means it can move subtly, and precisely to track an off-center. But this brutal, in elegant plastic gear train can't possibly, be used for the tracking and. It isn't just, like the Philips system this lens is floating, and can move up and down but, unlike, the Philips system this, lens can also move left and right with. The help of a diode I have lying around you can see that the laser can move quite a bit to either side, let's. Take off this plastic shroud to get a better look this, one is perfect. For showing this yes, okay. I'm sure, you can see these rectangular, coils, surrounding, a vertical structure these. Coils will push the lens upward if a voltage is passed through them but. If you look very carefully you'll also see a pair of circular. Coils on the outer edges when, a voltage is applied to these depending, on the polarity it will attract itself to these handy, magnets, placed on the sides or it will push itself away, this, causes the lens to pivot either left or right depending on which way you slice it the best part of this setup is that the lens is completely. Independent, of the sled that it's riding on if the sled moves a bit it doesn't care they will just react to that movement as though the track of pits it's tracking. Has moved slightly that. Means that the sled only has to move in course steps and the lens will take care of the rest but that's just one significant, difference the, other is in the photodiode arrangement, you, may have seen the term three-beam. Laser tracking. Before. Or something like that in these, systems rather than using only for photo diodes, like in the philips system we use six in, the middle our four cells arranged. Actually. Exactly like the philips system these are used in an identical fashion for, focus an elliptical, reflection indicates an out-of-focus beam and as orientation indicates. If focus is near or far but. To correct tracking, errors two additional, diodes to either side are monitoring, for an off-center being in these systems a diffraction grating splits, the laser beam into three in reality. It splits into two infinite beams of increasingly, weak intensity as they deviate from the center but we only care about the center beam and the two immediately surrounding, it now. When, tracked correctly the outside, beams shouldn't, land on the stream of pits they, should instead land just outside of them which, will that's caused them to reflect the featureless, boundaries, the, reason this works to track the stream is that if the track deviates, suddenly. One of the tracking diodes, will start seeing the data stream that's. Not supposed to happen, so the player will react by nudging the lens in the direction of the activated, tracking diode this system is certainly more complex, on the hardware side but, given how simple the trigger is no, need to compare ratios simply see if a single, thing is happening it's, probably, a lot easier to implement however. This, makes me wonder if the system is fundamentally worse, at tracking, disks see. I've heard anecdotal, evidence that the original Philips single beam tracking, is superior, at tracking scratched or damaged, disks and with. The knowledge of how the three beam tracking works that. Kind of makes sense, imagine, a scratch appears, just next, to the data stream if that, scratch is bad enough it might Bend one of the tracking beams toward the raw data stream causing, the lens to deflect for a defect that isn't really there what's, the Philips system it wouldn't see this scratch because it only has the one scanning, beam it, would ignore it and thus be unaffected now. Of course these conventional, systems aren't remarkably, inferior, they can tolerate scratches, pretty well too but. It makes me wonder if there is truth to the anecdote, that the swingarm servo, Phillips single beam tracking whatever is, indeed superior one, last thing before we answer why this became the standard I'm, not afraid to tear this apart and find what's inside so first, you can see the actual laser diode here as opposed to the Philips machine where it's housed in this plastic this, like in the Philips setup projects, the light sideways, where it hits a prism gets, shot up at the disk surface which the floating lens helps to keep tracked and focused and it gets reflected back goes straight through the prism and lands, on this little chip here now.

This Is interesting because on this machine we can actually see the backside of the photodiode, array unlike. On the Philips machine where we could only see the board if I keep going to remove the lens and get everything apart you can see the prism in here take, a look it does a great job of reflecting light at a 90 degree angle and now, let's see what we can see of the photo diodes well. Don't get your hopes up they are pretty much microscopic. To, be fair we are dealing with laser light focused, on microscopic. Pits so it stands to reason that these are probably, pretty small I don't have a microscope, handy yet. But. I do have my ridiculous. Macro lens set up so I could get these extreme, close-ups, you, can definitely see, that these are three clusters with one used for data capture and focus, control, and the to to either side for tracking to. Show how small this is I've placed a dime next to it for scale for. A more international perspective, how about a microSD, card and just, for fun here's the point of a safety pin these, really, are tiny, so, now why did Sony's floating lens and stepping platform, become the de-facto method, of reading optical, discs with. More photo diodes and greater mechanical, complexity, you, might think it to be inefficient well. It may be inefficient, in some ways but, in most ways it's in fact much more efficient. First. Let's take size if, we look at the Filip system you'll notice that the entire laser, pickup is essentially, behind, the disk the. Pivot point for the swingarm has to be farther to the rear of the player otherwise. It would simply rotate around the circumference, of the disk and that, would it be very helpful this off the bat limited, its potential to miniaturize, and boy, did this get smaller quickly, portable. CD players burst on the scene in 1984. And they would only continue, to get smaller with, one CD, player featured by tech Mon actually, being smaller than a CD, and that was in 1988, the same year as this Philips machine was made in fact, this very mechanism is larger than it needs to be if these, parts were shifted downward, it could be no longer than the distance here and this. Laser platform, could get smaller and smaller and smaller until, eventually you're, into modern, slim drives for pcs which have the tiniest, of lenses and thinnest, of assemblies, and the PC, market would only continue, to make this Philips system harder to justify in fact, one fatal flaw of the Philips reader would make sure it fizzled into obscurity its, mass, imagine. In a portable player which can be set in any position or even moved around while playing that, it had this swinging, laser pickup it's, so loosey-goosey. That it's doubtful that will track very well and its. Mass also limits how quickly it can move when. Cd-rom, drives appeared, and getting, faster, and faster and faster the. Laser would have to be able to wiggle itself back and forth at frequencies, in excess of 10 kilohertz. That's. Easy if you're just wiggling a small piece of plastic back and forth but, a lot harder if you're wiggling this big swinging, thing and so, Sony's three-beam, laser tracking, would be miniaturized and improved over the years developments. An anti skip functionality, meant that CD, walkman, could be tossed around without fear of skipping, or glitches or getting, stuck repeating a bit of the track that. Was accomplished, simply by reading the disk at faster, than normal speeds creating, an intermediary, data, buffer, between the disk and the processor, the, DAC could have upwards of 40 seconds at its disposal for the laser to get back on track and resumed the data stream which, thanks, to the timecode is easy to piece together if a problem does arise thus, eliminating, the effects of skipping and of course later on the wavelength of light would change to read packing, the pits closer together and creating the Meuse high-definition, laser disk and then, later the DVD, and obscured digital format you might have heard of later. We'd say enough, with the read in with the blue and, we'd be packing upwards of twenty five gigabytes, unto a slightly different silver, plastic thing after.

We Briefly, re-enacted, the videotape format Wars of the 1980s, because, why not but, we're getting ahead of ourselves there's, lots, more to talk about when. We next check in on optical disk technology will. Discuss the yellow book the standard published in 1988, that defines the specifications. Of the cd-rom, then. We'll talk about some writable, dis technologies, like CDR, and cd-rw and. Then, if interest persists, we might dig a little deeper into the DVD and some of the follies of its development such, as how this logo mysteriously. Features a disk for, a solid-state. Memory format. Hmm. Thanks, for watching I hope you enjoyed the video if you missed the first two videos on the compact disk you can check them out in the playlists on digital sound that will quietly, pop up above me so. Serene, as always. A great big thank you to everyone who supports this channel on patreon, especially. The fine folks that are scrolling up your screen if you're, interested in pledging some support to the channel to help it grow please, check out my patreon page thanks, for your consideration and, I'll see you next time. Hey. One thing my most viral, video to date was about how Sony used the tracking servos, and a CD player to create the copy protection scheme, in the original PlayStation, you, might want to check that video out but be, warned that there are a number of annoying, things, about the flow of information over, there it. Goes into a lot of detail, about the PlayStation, and some of its history and the comments, on there if you dare to look at them indicate, that many people were, not. Happy about it so if you haven't seen it check it out and apologies. In advance and. Another, thing, so, if you didn't know there's a second, channel technology connections. To where, I upload weird. Stuff from time to time and I, just uploaded, a video of a couple of CD players that, are very similar but have some unique differences, so if you want to check it out please, feel free to click the link down below or, up above.

2018-09-30 15:07

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3:12 nice camera movements!

Aside from the recent lower than normal investment, not to mention general consumer use or lack of consumer acceptance, optical storage is king. Magnetic storage has the crazy high capacities, SSD storage (various technologies used) has the crazy high transfer rates and optical storage, at least for me, is the only media I fully trust to last through the years (ignoring manufacturing defects that can affect any medium). Ok, one other medium I trust is film. However, I'm unlikely to store digital information on film so I didnt think it relevant. I'm soon to upgrade to a BD-XL writer. Its a shame that the 100GB+ BD-r's are so much more expensive simply due to lack of demand. But hey-ho.

Good video, kind of reminds me of the old school yank documentary's made in 1930 to the 60's, only in colour. None of this modern amdoc bullshit.

"Enough with the red, in with the blue"! Nice

"Complex thought?" From YouTube comment sections? Oh, honey, noooooo... *THAT'S* not gonna happen....

your funny

Lool you changed to a red shirt. Also, vrry unfirmative.

I really enjoy your videos. Most channels assume their viewers are too easily distracted, but you aren't afraid of alienating viewers by diving deep into technical details.

Watching this, I realized I am *such* a nerd. Love it!

Philips pickup was crap. There dvd recorders was a joke too for the pickup. There pickups was cheap with plastic tags holdings the lens unit which ended up dropping on one side and then could not track. Seen many of them for repair I had to do. Got worst with dvd recorders because the heat made the plastic melt and went completely out of line.

Please keep making this series and do a video on blu rays and hd dvd.

“Big swinging thing” Hahaha

Wow, the salt in this video

18:56 "Enough with the red, in with the blue" - Master stroke

I still make CDs to this day

Marketing fail: "3-Beam Laser Tracking System" should have been "Infinite Beam Laser Tracking System".

Keep in mind that 'a little more precise' just turned out to be the difference between CEO, and CEO/Chairman.

My undergrad was based on the HSC08 they're known as "Spyders"

Love the outro music. It reminds me perfectly of my youth spent watching PBS educational material aimed at the young nerd crowd. It's fun when you realize, the jocks and nerds have always been, and without the intellectuals, engineers, and curious types that have always been with them, the jocks would still be throwing spears in loin cloths rather than javelins in gym shorts. :-)

"Service these things"... Would you give that to Mr. Carlson's Lab for repair? Servicing of these consists of ordering new parts from the manufacture so they can make even more money.

Interesting stuff. I never thought the data coming off the disc looked the way it does. I wonder what that sounds like. A little off topic but I have this Halloween jack o lantern sound and light box that plays different messages. It has two chips inside, the smaller one I know is an amp chip because there's a volume control and the bigger one I know has the messages recorded on it. there's a number on it. FFT700006A. Searching this number turned up empty so I'm guessing it's a custom made chip.

Play your CDs over Bluetooth x 3

Many times I've been able to find datasheets by removing suffixes of part numbers.. I'll remove them one by one until I find something, if anything

I have to agree that this is very valuable education. I've seen your videos before, didn't expect them to be so in-depth and thought that I couldn't learn much but was proven wrong. That being said, I just want to comment on your ...I don't know what it's called but you come of like a total douche, specifically at the beginning. I recommend emptying your bank account, taking about a year off and drinking a lot, even drugs. Make sure to wake up next to at least two strange people. Get in at least 1 fight, hitchhike or road trip across the U.S. and back, following your favorite metal, techno or hippie band or just going to a lot of shows and clubs. Get to know some hardcore criminals, you don't need to rob a convenient store or anything, just befriend these people and gain their trust or respect. Make sure to attend at least 3 parties that involve more than 1,000 people and do something involving an adrenaline rush that nearly makes you piss your pants at least 6 times (not counting the things I mentioned above that may give you a rush). I think you'll have that douche vibe out of your system by then. I think you'll find that life is much more awesome after all that as well and not as sensitive to criticism. cheers.

I can't wait for part 2! Things are getting juicy now

Wonder how Pioneer CD players work, since Pioneers are the only ones that can read badly scratched CDs

Hello could you explain monocrystaline turbine blade technology and platinum aluminid coating that prevent hot corrosion ? I think that would be right up your alley

> "wiggling this big swinging thing" hurr hurr, I'm 12 :B

Dime? Micro SD card? Safety pin? The internationally recognised comparison standard in the banana! :) (Excellent work, love the show!)

Nooo! I need to know why the SD logo features a disc NOW! Damn cliffhanger! :)

You shouldn't have covered how tracking works... Just to piss people off.

The swing arm was more durable, it did not need lubrication.  the gears on the sled would bind up and were cheap plastic. It took more time to assemble the swing arm setup, because more alignments were needed. I worked with them on jukeboxes.

It's unfortunate that Sony won. Their lasers have always been trash. 95% of the repairs I did to PS2s were replacing worn out lasers. Over. And Over. And Over. While other devices were exploding capacitors or just wearing out mechanical parts, Sony managed to take something that should last for a decade and turn it into a consumable.

I love this channel, the content is getting more and more informative, professionally explained and not boring at the same time with a little jokes here and there. Good to be subscribed! Nice little touch with shirt color haha

13:21 Not infinite beams, that is impossible! Though many more beams than just three are possible. The diffraction grating creates beams separated by a fixed angle, so divide a half circle by that angle and you get the total number of beams...

I mean, as far as I understand you can use the best of both worlds by having a fully floating lens and no swing arm to ensure miniaturization, while using only 4 photodiodes to have better scratch tolerance. Philips system might have been left behind also due to stricter commercialization of chips that could implement it compared to sony system. For sure smaller company are not going to make their own, so they are going to use the system that's more accessible.

BTW the secret to showing small signals on a scope is to have a very good ground. Any wire essentially forms an impedance so that clamp on the probe is only good for fairly stong and/or low frequency signals. If you want to go down in voltage and/or up in frequency it's best to use the ground near the tip of the probe.

I jumped to an collusion before I finished the video...I couldn't help myself

I love your videos, keep up the good work. :D

I tried to find your other channel by searching for "Technology connections" it didn't show up (?). I was able to get it via the link to your '"Tale of Two CD Players" video.

I fell asleep at 2 minutes in.

Some men just want to watch the world learn.


Once again - excellent content.

Cool t-shirt :D i want one :) greetings from Poland :)

Dude! I love your videos! Can't wait for more!!!!

Maybe there is a difference between media. Sony media cdr seems best to me. What's your experience?

How on earth did you find an instrumental version of the outro song??? Is it from some lens cleaning disc or something? Fantastic video as usual.

wow you're smug. way less cute than you think and nowhere near as funny.

I love these videos! And I can't wait until you get to the burners, ESPECIALLY the rewriteable ones, those have always been a mystery to me, and I've been too lazy to look it up for myself.

Wow, this channel just gets better and better. :) Thank you for the interesting video! :) I've really enjoyed it during supper, it was properly relaxing for me (kept my attention and shown some interesting close-ups). :)

100% sass in under a minute, love it

No microscope yet? Take that focus lens, stick it in front of your phone camera (I hold it with a paperclip). Voila, now you can take pictures of the photodiode die and actually see something, there's usually more than just the diodes on there.

you are wonderful.

kenwood uses the same setup as a sony

that was the most _passive-aggressive & diplomatic_ way of calling those people _whiny a-holes.._

Does anyone else think this guy should run for president one day?

I love the production quality of your videos. I also like your sense of humour and little twists you add to stuff like watching yourself on an old video or playing parts of the video through a different screen. Top notch videos good sir!

Oh, and longer videos are totally ok! I watch your videos for the explanations so more explaining or details is never a bad thing! then again separate videos for more specific stuff is great too. lol. what i'm saying is I love learnin from ya ;)

Do you get your background up and running with the lava lamps and all each time, or do you ever use a green screen and and just put in in later?

Sony and Philips actually wanted people to be able to copy digital music tapes to which they had many threats of lawsuits by the RIAA and subsequently at the core of the Multimedia Compact Disc vs Super Density (SD) format war was DRM. The combined DVD format includes copy protection but took the more restrictive route of encrypting data. Later renamed as Secure Digital in reference to its DRM capability SD cards were developed to provide copy-protected distribution of music. In fact all an SD card is a MultiMediaCard (MMC) developed by JEDEC and then copy protections are added to it. (SD being the superseding standard tightened up various specs to increase speed but DRM was at the heart of the standard). And DRM has been a cancer ever since. DHCP anyone?

But I want do know why there is a disc in the SD-logo NOW! :P What a cliffhanger!

I just gotta say that your videos have gotten so much better. I was gonna complain about the lack of graphic representations and demonstrations in your earlier videos, but you've fixed that. Keep up the good work.

18:56 That shirt colour trickery was pretty clever.

Your attitude is the second best part of your channel behnd the knowledge!

Called it about the microcontroller from the last video :3 Purpose built and doesn't do most of the datastream work.

nice work

18:16 Are you a fan of the Technical Difficulties, or is it a coincidence that you both use the same gesture for "seedy Walkman"?

Reminds me of early floppy disc systems. Certain systems had their own chips, even going so far that they had a whole board. And that would control the drive. Other systems were very bare in the floppy drive and had to be controlled over the wire. Guess what, yes the everything inbuild floppy drives where bigger and more expensive but gave less trouble.

Lol, "more random singing " the villagers cried. Love your videos btw, long time watcher and this is the best video yet. Keep up your very good work.

good job on the captions.

very interested to see how RW discs work!

0:44 *_And that's how the world gets better!_*

Uh, I hate to say this, but you're factually incorrect. This is, in fact, *NOT* later, as you state, because I am yet to watch the first video. Further to that, I needed a way to add just one more comma to this post.

You might want to have a look at the proprietary GD-ROM format created by Yamaha for the SEGA Dreamcast and Naomi systems.


Had to watch that again for the little musical section! Joy!

Anti-skipping is cool. But it was damn expensive back then and deserves some explanation. You see, the idea of buffering the data stream so that the drive can take its time to pick back up on the stream if something happens is cool and all, it helps to reduce the size of the player (since there's no need for huge shock-absorbing rubber assemblies), but there's a crucial detail missing: to buffer the data stream, you need memory, which was very expensive back then. The first anti-skipping systems only had just under 3 seconds of buffer time. Now that might seem very little, but take that - to store just under 3 seconds of PCM 16-bit 44.1KHz stereo audio it would take 512 KiB of RAM. Not to mention you also need to include a DRAM refresh circuit, because SRAM would be just insanely expensive. Even in 1992, that would cost a lot for a portable CD player. Some players did indeed use such amount of memory. Until someone (perhaps Sony) had a brilliant idea - why not compress the audio before sending it to the buffer and then decompressing it before decoding? Using 4-bit ADPCM compression, one could fit the same 3 seconds of stereo audio in just 128 KiB - the quality would be slightly degraded, of course, it would sound a bit noisier to a careful listener, but that meant that portable CD players with electronic skip protection could be a lot cheaper - and it wouldn't really matter if the sound was a little bit worse if you were listening to music in your car with the engine/road noise, or outdoors with all of the city background noise helping to cover it up. And as memory costs went down, we began to see CD players with 10 seconds of ESP, 15 seconds, 30 seconds, and even those which advertised themselves to "almost never skip".

Well Done Mate.

While enhanced precision on your part is always welcome, I wouldn't get your hopes up too far about the other end of the bargain...

I'm afraid that you may be starting to alienate some of your adult viewers with the comedic avenue you've been starting to take lately. Just putting it out there. Don't want it to be true, but I've been cringing a lot more often than before.

Hi, great job. What about to go back into Laser Disk technology with neon laser head? Can you show how it works there?

I just like this guy. So informative and entertaining. Time just flies when you're having fun.

Great video, but you probably should warn people not to poke around inside their electronics when they are powered on.

18:57 That was pretty cool!

Your production quality keeps getting better.... kepp up The Great Work.... I still miss the theme tune though.

as a non native speaker i weigh your words carefully and i expected you even to give this its own video!


If you want an interesting technological rabbit hole, the issue of the pre-emphasis flag and why the Redbook format included it, and how it was supported (and required to be supported) by hardware is pretty fascinating.

Mate - fantastic!

I enjoy falling to sleep to your videos as they have the perfect balance of monotone, video length, and interesting information, to keep one from being bored, yet not so interested as to actually watch or stay awake for it all. Just kidding (sort of). Really Great tech videos. Thanks!

When probing small signals you can't just have that earth lead connected anywhere. It act's as an antenna and picks up the noise you are seeing. There's a proper probe for that that has just a short bendable pin sticking out, that you can touch the signal ground close by with.

40 seconds read ahead sounds a bit too much for the time, maybe 4 second anti skip at most. music CDs are encoded in WAV format and 40 seconds would be close to 7 megabytes in size. The biggest portable memory at that time consisted of 1.44 MB floppy disks.

You're the best, man. You really are. Amazing video!

That sass was delish!

It's awesome how you can call me a twat... and agree. I will pay more attention, I promise, if you promise to do more of these unscripted videos, you know... so I don't feel so alone?

9:14 I prefer a little bit more order to my disassembly with intention to reassemble

I used to love taking my old cd players apart and now I understand way better how they actually work.

I fucking love your snark and sarcasm. Keep it up!

Do you plan on going into detail on the differences between CD-R+ and CD-R- that plagued my parents when I told them I needed blank CDs to back up our PC data those so many years ago?

Don't let the dickhead comments get to you; these videos are fantastic and very informative with just the right amount of silliness.

Hey, you thicc bastard. Dont you tell me how to be. Love your channel.

Wow, the snark is strong with this one! I'm enjoying this attitude

Open your ears people!


(20:12) Because that is your most viral video ... have you considered remaking it to improve the information flow? Because that's an easy way for you to earn views/money/subscribers, plus the overall quality of your videos will improve.

That SD logo = mind blown

Red to blue

Thanks for sharing your outakes reels! Becoming a public figure is a PITA isn't it?

For The sake of being portable, faster and mass production friendly, they have completely disregarded the high fidelity aspect of laser pick-ups. It is good idea to hold on to the CD960.

Rule number 1 of photodiode circuits: don't measure a photodiode with a regular scope probe. Instead use a active (FET input for frequencies less than 100 MHz) probe for high gain at low noise. Or similarly, a fast FET input op-amp.

:/ 21 minutes in what could have been condensed into 5 minutes. So much pandering

Incredible work as always. Can't wait to see more.

The More You Know *music starts playing*

Thanks for the technical info. :-)

Why are current music players seemingly incapable of seamlessly running two tracks back to back? It's kind of annoying to hear that half second of silence between two songs that flow into each other. Pink Floyd did this a lot, and both my PC and portable music player (phone now, but formerly MP3 players of several models) have this auditory gap.

don't understand anything you're talking about, but your right hand alone can hold the entire internet. true.

I've enjoyed this channel since the beginning. I won't say the increase of jokes bother me, jokes and quips can be entertaining. But I love this channel because how you distribute information to us. You speak in a pace and dictation where it allows my brain to hold on and actually learn. So the memes like jokes, or jokes that don't come in naturally, are a bit jarring. You'll find a rhythm for that in time, so I'm not saying stop but maybe don't feel pressure to squeeze any in. Love it keep it up.

Definitely interested in understanding the tech behind Cd-rw, never understood the black magic that went on with that stuff.

Wow you're a sanctimonious ass. What a way to talk down to people.

Go fuck yourself you pedantic patronizing peon. Unsubbed.

Criticism time! That Sony player is about 5 generations newer than the Philips. Unfair comparison.

Hey @Technology Connections, EEVblog just did a video about a video microscope this week it might be a useful tool for you.

The lens trackig here looks like it was what later became the autofocus systems in phone cameras :P

Is it just me or has there been a noticeable jump in production quality? It also seems like you’re more comfortable with the camera and the mildly-self-defeating humor (which does seem like a good approach to disarming any grumbles about the geeky nature of the content without having to forgo the geeky, in-depth explanations) make this video one of the most entertaining I’ve watched on this channel!

The most polite rant ever ;)

By the the Philips CDM-9pro was legendary in performance especially dealing with disc defects. The Teac Esocteric disc clamping mechanism was an outright tank. V.R.D.S. system was crazy good.

Yes the pulse dac is a fifo 1 bit DAC. Sony was always more in the systems approach. I love the Japanese.


Where did you connect your ground or your return? Noise can be an issue due to your connection. I love O scopes.

36 seconds I am jumping to conclusions. Ah that is so much better typical internet responses. I owned a Sony XA-7ES. Amazing CD player. Was curious about Philips but that would be it.

I don’t want anyone scrolling up my screen!

@11:00 the Philips mainboard was also used in multiple models for multiple brands, though it isn't marked as such. I think the number on the red label is the code number for the final assembly, indicating for which model it was stuffed (only by looking up the number, no obvious correspondence). Putting everything on the mainboard might have been cheaper to mass produce, even if a modular approach is neater from an engineering point of view. Most mainboards would have been used for a shorter production period than the mechanisms, so really no need to adapt the board during production to for example accept a CDM9 instead of a CDM4. If necessary, they probably would have done so or made another CDM version without skipping a beat, anyway.

Keep going all the way with the compact disc stuff

I've always disassembled electronic & mechanical stuff that others have tossed out, just to satisfy my curiousity about how things work! Occasionally I'm able to pin-point where a fault is & fix it, so I'm always keen to learn more like what's in your videos!

"I don't know how people service these things" -- well, that's about the start of our Throw-Away Culture. You don't service things, you throw them out and buy a new one.

Love the videos! Keep them coming!

I'm a fan, but I can not get over that you look like someone skewed Robby Rotten about 11% horizontally. It just can't be a coincidence that you chose the same hairstyle and just happened to shape your eyebrows that way? The odds are 1/gazillions.

It was mind-bogglingly fun to watch you sing! I sing on most of my videos and this was very validating. I love everything about this channel. The presentation, the information, the photography... The best!

1-bit DAC? But that's just a buffer!

Over 90 % of folks commenting have never created a video and do not appreciate what it takes. Thanks for the video!

FYI that little up and down dance the laser does when looking for a disk as called the 'focus search'. Love the vids! Keep it up!

10/10 polite commenter thrashing

You and I have the same scope. Love that Rigol 4 ch.

please do one in depth for Minidisc

That magnavox player was my first cd player

I'm not sure if the intro was a joke, but if so it really didn't land.

Honestly, I think responding to the comments section in your subsequent videos is just lowering yourself.

I have a bang olufsen radio (BeoCenter 9500) that has a Phillips tracking system

Don't belittle your viewers by telling them they jumped to conclusions.. the reason people were asking you about the additional details was because people are interested, and are watching your videos! Be appreative, and take their demand for more info, and their corrections as a compliment, because as I mentioned, it tells you people are paying attention, they're interested, they're involved and want to interact (instead of just silently moving on).

Your camera is focused on the osciloscope, you look a bit blurrrry. Loved that song btw.

I think it'd be interesting to see a later video cover PC disc drives, how they compare to dedicated players, and whether or not some types of disc-playing software are inherently more sensitive to faults on a disc than others. I know a couple of my CDs either skip all over the place or outright lock up at certain points when I try to play them through iTunes, VLC, or Foobar, yet work just fine in a normal CD, DVD, or Blu-ray player as well as in Windows Media Player. Similarly, DVDs on VLC sometimes have an awkward pause during what I assume is a layer change, yet progress smoothly through these points on a normal DVD player.

LOL, look at your shirt, dude! Just the perfect color for an electronic weather map, haha! (So similar to your blue box and lamp that they would want a piece of the map action too!)

UHHH-OHHH, guys! He just chewed y'all out a good one!

Previous video: "Huh. looks like his hand has had a nail slam through it. ah, but he has been handling printers. must just be toner that ended up mixed on his hand" This video: "Plaster on hand? .... oh.... ooooooh... huh."

Its weird that you can communicate with the hosts of tv shows now

Oh! Now I know why you made your shirt so weather-map compatible! So you could key the red over it, huh? But then how did that not also affect the very similar blue in the box? Probably because you could box your shirt into a border that controlled how far the change effect would travel? Or how, exactly?

If it was not for digital what do you think would have come after blu ray. Would it be a even sharper "ray" or would we have gone to Cartrage. Like sd cards loaded with movies and for games it would be proprietary like handhelds.

UHHH-OHHH, viewer guys! He just chewed y'all out a good one!

Has anyone asked about Mdisc?! We need to know more about that!

Do a video on how the scope works. Also great suspenseful narration during the tear down of the disk changer

Drop the defensiveness at the beginning, people nitpick, reacting to it like that looks petty.

Loved the diffraction grating part!

Thanks for the video

I like the shirt change from blue to red, back to blue. Dig it.

Is Alec a formally trained engineer or just a scarily well-informed nerd?

Hahaha absolutely stabbing intro! You'd think people would be patient or listen completely rather than tuning in and tuning out.

I‘ve had several „standard“ CD players, that started to get very prone to skipping at the slightest bit of shock to the case once they got a few years old. Even the bass of the music itself was enough. Someone told me that the swing-arm system was much more solid, so I got two Players featuring this design. Both these are from the early 90s, and you‘d have to hit them quite hard to get them to skip. So is there a reason that the Philips system is more robust or did I just get lucky with my two great-working players?


Tracking Reading...Integraded has no movements at all...

Intel Amd...memory is better INTEGRATED....USB...Hard drive is slow.... scratch skip magnetic...silicon Spike some film silver metalic...INTEGRADED IS THE BEST...SERVER MEMORY NEED TO GROUNDED PONTETIAL WINDOW 98 SPECIAL EDITION IS SERVER IF MEMORY NO MOVING MECHANICAL......

I KNOW i saw...she put me the one the falen same Vluna Qc Kilauea

another great video

Ok, ok, I'm really nerding out on this. CD technology is severely underrated, considering how quick the lens has to react to stimuli the reflected laser creates. I did read a book fully on CD technology from Sony, pretty much from cover to cover, never did find it again.

Actually I remember seeing a mechanism that was non-linear so the CD could run at a fixed speed like a record player.

Nice Bill Wurtz nod. :D

I love your channel. I'm reminded of the Bang&Olufsen tangential-arm vinyl record players. To avoid tracking errors the pickup is moved linearly across the top. A very light tracking arm will track the grooves, and on the other end is an arm with two microswitches that will realign the arm to perpendicularity if the pickup engages the microswitch.

Sony was the one which forced Philips to do 120mm discs. Knew that much! Look at DVD and Blu-ray with the same diameter and spindle hole!

8:33 innie-outie-turny-turny

Oscilloscopes are more important than people

In future CDROM videos, I would like an explanation on how CDROM got so fast. We went from 1x to 52x or even higher speeds, and very fast writing speeds. Just a case of better processing and faster components, or did algorithms change to deal with spinning discs at thousands of RPM?

Did you get that changer back together and working?

Please don't become Techmoan, don't start to fight your public. It's great to know you read your feedback, and you definitely manage it way better that Techmoan. But I still think there are more gentle ways to handle it than the pasive-agresiveish one.

CD was never intended to be quality. As they wanted it to be they wouldn't use crap stereo mixed analog masters and converted them to digital. It took until the late 90's before they fixed by completely converted every single track from the masters to digital. It was done for the SACD releases, only since then you can enjoy the albums as they were intended to be. So throw your crap CD through the windows and get a decent SACD copy.

lets see dvd and blu-ray covered next. get all the formars in there. and hell while at it lets look at more video formats. whats the earliest video format we’ve explored Laserdisc, VHS and Betamax? what about photography? thats been around since what the mid 1700’s?

Speaking of sony... you might do something on the versions of ps2. I was recently digging around in two different ps2 slims, and i then realized that I had two different versions of ps2. There is also two more versions of the the ps2 in its fat form factor. It was pretty remarkable to see the same original device made through that many revisions and sony seemingly pushing it to be smaller and smaller and then building it into the ps3(it was removed in later versions of ps3).

Do a comparisson with sanyo laser pickups too

I love this guy

How fucking condescending can you be? I like your content and you're entertaining but don't be so condescending. Or maybe were you being pedantic? Feel free to correct me.

18:04 Me too. I often find it's a lot harder wiggling this big swinging thing

Yes it's more robust. But problems with Sony players are usually due to bad caps on the board that lies under the laser, not the laser itself. I have replaced a lot of these caps and afterwards the tracking is much better, often nearly as good as Philips with some tweaking of the Focus and Tracking gain.

+Spinler Muckflitt ; Not just CD players, & our 40C+ summer heat-waves aren't kind to components like them & even worse on rubber belts & pinch-wheels, etc.!

+MrWombatty With CD players, it's all about bad caps

+Spinler Muckflitt; That's why I'm so glad my Pioneer PL-S40 turntable from the mid 1980s is a quart-controlled direct-drive unit! Cost more than the belt-drive version, but certainly worth the extra I paid!

+MrWombatty Belts are my nemesis

+MrWombatty I always wanted a direct drive then but window shoppping was all I could afford. They always had a lot of Pioneer in Laskys Hfi shop in my home town

6:45 The disc matches your shirt which matches the shelf room which matches the lava lamp which matches the disc!

If you want weird optical disc mechanisms, there was a CD-ROM drive with two laser and lens assemblies on a rotating platform. IIRC it used one to read normal discs and the other to read CD-RW. I had one that came with a used computer. Then there was a much older drive that had its laser on swing arm instead of linear rails. I assume the reasons for such oddness were to get past certain patents. Another oddball was NEC's linear actuator floppy drive. Instead of the typical 3.5" drive grunts and groans it sounded like an old ST-225 MFM hard drive, but quieter.

For some reason the clip of the disc tray going in and out repeatedly with the cut to speed it up was extremely stressful to watch

I will be great if you make a video about 1-bit DAC, that you mentioned here. The ideas behind it are much more interesting than mentioned before simple resistor based DAC.

Cunningham's Law coming into full effect.

HD DVD>Blu-ray


thats exactly how the world gets better,......but noone wanna believe me.

3:04 I made some smart ass comment that I don't recall, to my school Superintendent. She told me to go home and ask my parents what "mind your p's and q's meant" and I told her "No Need, it means mind your pints and quarts". Her jaw dropped, then she gave me detention for three days. I had been walking home, technically no longer on school property. I keyed Bitch into the hood of her Mercedes. She retired a few days later. I was 12.

We don't make mistakes. We only have happy accidents

Love your channel, Hate anything Sony. They screwed me over on a un-repairable 2 year old $800 Handycam....never gave them another dollar.

complex that's funny. i think you over estimate the folks that watch youtube.

Wow you waffle so much in this vid bro. Im ten minutes in and im bored. Ill catch ur next vid.

that was the smoothest way to say F you to people that don't pay attention I will be using it

I've never noticed the disc on an SD card. Wow I want to know if there was some kind of Secure Digital optical disc.

I don't know if I love you.... Some of your preaching I don't enjoy (the turn signal lights thing comes to mind, while I agree with your desire to have the Euro standard be worldwide, I dislike the idea of having it mandated) having said that perhaps maybe I'm not your target audience... Though you mention techmoan. I love him...... Having said that... It's not a huge deal, but the intro turned me off... Especially the bit about my not doing my part... when I actually DID wait patiently for the next video.... "And perhaps you dear viewer could refrain from jumping to conclusions quite so quickly..." Not, "perhaps those viewers" not, "perhaps some of you viewers"... ME... Again not a big deal, but you just got done talking about choosing your words more carefully... and to my ears, in almost the same breath I feel you chose badly... Meh... My 2 penny's probably aren't even worth that, so hopefully it was at least worth reading...

Useful info, but could have been condensed to about half the size :/

I think I had that exact same Sony changer back then... I also had a DAT recorder. I felt 10 years ahead of everybody else :)

Oh, I think I'm getting a new notification ringtone!

Thanks for calling out those dipshits

This is very educational and I'm also interested in old technology glad I found and subscribed this channel keep up the awesome work

*grunts questionably* What be this deeveedee devilry ye speak of? Seriously, I really dig your videos. I've learned some interesting things from this channel. Your retort to the troll brigade was pretty priceless... I had to explain why I was laughing to my boss. This didn't have the same effect as the vid. Something about explaining a joke or something funny just sucks all the fun out of it. I genuinely look forward to the next vid.

Thank the lord for youtube content that isn't dumbed down. As the mainstream media moved away from quality technical content since the 60's and slides further and further towards the lowest common denominator they guarantee their own extinction.

A conclusion? Get my big boots, it's jumpin' time....

damn. you got me with the shirt changing. xD didn't even notice till you changed it back to blue.

Touchy as always...

you are very clever.

I also thought that nowadays, CD/DVD/BD laser heads have multiple sensors, reading multiple tracks at a time, essentially skipping several tracks at a time, because they'd be read by another part of the laser.

I admit you lost me early on (not your fault) but I stayed to the very end. I appreciate the big effort you make only to lose my attention. Please keep making your content - I really do appreciate your work.

I dont understand the 'ding' thing everytime the last video is mentioned....whats it mean

dis vidoe vas uploded to slov!

At least Philips didn't put Malware onto their music CD's ...

Umm wasent there a video of an obscure disk system that was smaller than miniDISK and used a pivot arm?

Yeah, DataPlay and that was very small so a pivot arm doesn't mean you couldn't shrink it.

"The trademarked SD logo was originally developed for the Super Density Disc, which was the unsuccessful Toshiba entry in the DVD format war. For this reason the D within the logo resembles an optical disc." You're welcome

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