there's no less technical knowledge with increased comedy/attitude so why not? not like the information here would actually be used to aid a live project, you're better off finding datasheets and techspecs to read if that's what you really need (such as those used by this uploader to create the video)
@@memberwhen22 Someone had a sad teenager life. If you're here only for the technical knowledge as you say, may I suggest digging through Wikipedia and service manuals yourself? You'll get even more info, and faster. Let's not pretend that short form UA-cam videos are the epitome of education, their main purpose is to be entertaining and you're here to be entertained. If you disagree with that you're delusional.
@@uwirl4338 Why do you assume that a desire for information without the fluff requires a sad teenager life? I'd love to hear your metal gymnastics for that
Didn't think you'd see me sing, didya? Rest assured that the intro is tongue-in-cheek. You'll have to forgive me for the snark, but I really do want us to work together to make the world a better place. And communication is a big part of that. Speaking of communication, this is a re-edit to further condense some segments of this video! Some patrons left feedback that made be realize it was all over the place (and to some extent still is). But, I couldn't cut it entirely from the video, as I said we were going to use the scope in the last one. So I'm hoping the roughly four minute segment isn't too much. In fact, there was a *lot* of stuff that I found with the oscilloscope, far too much to fit into here. If you want to check it out, see the link in the description (and there's lot's of other good stuff in there, too). And don't forget to check out the third video on TC2!
What was hilarious to me was when you started singing a second time and then immediately cut it off. For some reason that sort of reminds me of the sort of humor I saw in the TV series _Bill Nye the Science Guy_ that I watched when I was younger. Or maybe I'm just weird.
I don't even watch most of your videos but I just wanted to say what you do is a public service to the world and your videos will be relevant and valuable for decades. I remember depending on one of your videos from years ago, just a few weeks ago. Your content is timeless, you're like a video version of wikipedia, keep up the great work and thank you so much for all the content you've already given us.
The P at the end of an IC's model number simply means that it is in a Plastic DIP package. Since ICs can come in different forms (surface mount, ceramic, etc.) it's often useful to leave off the trailing P when searching for data sheets.
and the XC stands for experimental circuit Mot speak for a chip that has not passed all quals yet. after it does, it is promoted to MC (Motorola Circuit) source: worked at Mot Semi for 25 years.
Hunter Scales: In practice, it was apparently also used for custom chips (such as this mask programmed one) that were as far as I've seen never given MC numbers. I've seen my share of XC as well as ZC chips in consumer electronics. Do you by any chance know what ZC officially stands for? I vaguely remember seeing TY on some stereo decoder chips for TV as well, would have to look it up to confirm.
I love the balance of humor and madness and information from this channel. It kinda feels like Vsauce, where it all began very clear cut and presented professionally, and now it's professional chaos that's greater than the sum of its parts. Not only is Technology Connections informative, it's art.
I've certainly recommended it to a lot of people. Hes more historian than engineer but his understanding is certainly improving fairly quickly over this past year or two. Either way I've been interested enough to watch almost religiously.
"I didn't know this was the Society for Pedantics!" "It isn't. It's the Pedantry Society." Also, the reason for the long plastic bar for the power switch being at the back as that a long plastic bar is cheaper than copper wires coming to the front, it is easier to install and less likely to be damaged with handling the player (wires need retaining and solder joints fail). Everything in consumer electronics was done for cost, hence why a single layer board when two or more layers would easily improve noise performance.
It's also to keep the 240V areas of the board confined to one small area, for safety. There are rules about that sort of thing, for CE type approval, etc.
@@GRAHAMAUS This is the actual answer. Separating mains circuits from low(er)-voltage circuits is serious business. You won't get FCC (and UL, and TUV, and so on) approval otherwise.
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.
Computer engineering student here, I learn about eletronics on my course, but because the focus isn't eletronics, I can't give you a very technical explanation. But when you tried to read the waveform from the diode, the problem was the way you set-up the oscilloscope and how circuits are designed. So I don't know how to begin to explain, but here it goes. The main problem is the noise, when you set up the osciloscope to DC coupling, the ground cable is the reference one and depending on where you plug it, this reference can be differente from circuito to circuit, so the first step I would do(I coun't see this in your case) is to use the ground pin from the IC and not the general one. This happens a lot in circuit design, because a lot of devices causes noise, you need to fix this when you are designing it and the easiest way is to make the VCC and GND to go along with the noise(simillar how XLR sound works), eliminating the noise and making that the circuit aways have the same electric potential. Another problem is eletrical things near the oscilloscope probres, where the cable is affected by near eletric fields(the raspberry pi 3 POE hat video from eev-blog, show this happening) and can be reduced by changing the path of the probes. A bad way to handle this is when working with digital signals that have a lot of pulses(PWM or similar) is to change the coupling from DC to AC. This is a bad way because when you do this you can't decode the signal and see if the circuit is working fine. But works. The best way to handle this, is to don't let any cable near the probres and keep them straight. If this isn't possible, the best way is to buy some low noise probres or callibrate the oscilloscope with the noise.
Mostly right. I just wanted to point out that if the device has an isolated power supply you could hook up the osc. probes across any two points. A rule of thumb is that it's never isolated so this feature of oscilloscopes is just a tease and conspiracy to sell fuses ;) Sometimes battery powered devices are isolated, as long as they aren't plugged into anything through USB or other shielded cables. Generally the only safe way to use an oscilloscope is to keep the ground clip on the correct ground (even this can get tricky). Just think of the oscilloscope's ground clip always being connected to earth ground and it makes a bit more sense that poking a circuit with that at random could short things out. [Edit] Hooking up the ground clip to a chip's ground could theoretically reduce noise, but odds are that chip is surface mount and the only way to hook it up is soldering an enameled wire to it, which then picks up noise and defeats the purpose. Plus, everything I said about hooking up to the 'correct' ground can make this impossible unless the device is isolated.
The photo diode signals from the Philips OPU are currents not voltages so they feed a virtual short circuit in the chip downstream so you should only see voltage noise there. . In Japanese OPUs the signal is a voltage. I designed a circuit to convert from the voltages back to currents while working for Philips Semiconductors to let Japanese OPUs work wiith Philips chips.
@@mikedjames oh, is that why modern sigma delta semiconductors that are mostly voltage usually have a I/V stage that then feeds a lpf to the output stage? AKM made an all current output delta sigma chip back in 2019 the AK4499. Supposedly it was the first ever made. Then they had a fire now the redesigned into a 2 stage chip set. One chip decodes the digtal and the other the analog output to cut down on crossfeed (in theory) It seems like Philips current semiconductor was the better approach with no conversion??
@@joesmith4443 you can either have a voltage source i.e. a hard switching transistor pair fed from a good solid supply - basically a standard logic inverter off the shelf, in a digital IC.. or a matched pair of current sources where the P and N transistors have to be accurately sized, i.e. an analog IC. When AKM went 2 chips that was because the digital IC process was shrunk so uses smaller geometry rules for cost and availability, while the analog part has to stay about the same size geometry for noise reasons ( digital chips can operate with so few electrons, analog needs more as each electron is a quantum of charge or a step in the voltage or current so you need to use many more to average out and get SNR to CD player levels - theres a limit with the current..) . and therefore use an older IC process.. The Philips servos also used a sigma- delta ADC , it had the advantage of having tracking frequency response up to about 1MHZ for large changes in the differential part of the loop, then filtered down in the integrator to a fewkHZ for the integral part of the loop.. As the detectors are photodiodes, it was easier to feed current in .. And the great thing about the Philips single beam tracking was it does not need to have the other adjacent tracks at the correct pitch spacing or even be present, so it could play better over dropout on the disc. But Japan wanted three beam tracking because must be better than single beam.. actually Philips used 4 photodiodes in a cross shape watching focus using astigmatism tricks, and tracking the spot in one go. So they could have called it 4 beam.
@@mikedjames oh I get it to a 2 chip system prevents thermal issues and since the “tasks” are broken down into two stage and because the analog stage can’t be smaller they can work independently without any overheating. (Hmmm, On a slightly off topic subject I am curious how Apple uses that new gigantic M2 Pro semiconductor chip for their new Macs. To me it just seems it better to break up the CPUs or break them up into different tasks like a TPU and GPU, etc) Yea supposedly Philips also made better noise shaping dithering modulators than Sony. I know this sort of stuff is above my knowledge but can’t one day the analog part benefit from Quantum computing. Or can “Qubits” benefit from a 1 bit simulator? Like a DSD PWM? Also why in most DAC chips datasheets they use either fully differential op amps or a single supply op amps in the I/V to Lpf and in the wild you see more dual op amps most implementation I “get” that having a dual Op amp prevent large swings but in just about EVERY older DAC chip like the Burr Browns, Analog Devices and Cirrus Logic they used single supply op amps and in most ADC they use fully differential op amps in the datasheets. Also the the non to inverted stuff is baffling? I get what it means but why would you want to invert the signal anyway? Does this cause phasing issues? All I know about those P and N transistors is that the discreet ones are more of challenge to match like R2R Topology “bits” but again like any chip solid state op amps makes this easier since the “gates” and resistors are well measured and guaranteed performance however some believe they don’t sound as good even if they have ultra low distortion and noise like the “3D Sound.” I just think that can been “made up” in a well designed power supply. The 3D sound is the one part that’s hard to master In Audio (I think). The Multibit chips of the past really did do a better job even if their resolution and specs are inferior to todays dac chips. However with Better resistors and computer algorithms I suspect that they chips would perform well above what they first measured in the 80s! Idk the DSP are good for certain things but for that 3D effects it’s all about hardware enigeering
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.
Excellent video! I really like your honesty in posting parts where you're poking around and making discoveries instead of trying to make the whole video look intentional. Keep up the great work!
Philips was indeed to close of a brandname to Philco. For lighting products, and cassette tapes they used the Norelco name. The clicking noise when slowing down the disc by hand is the laser freaking out and swinging into its end stops. And about that service thing, Philips had extension cables to rest the CD drive aside of the main PCB.
The Norelco name was afaik slowly phased out after they purchased Magnavox (and later Sylvania and Philco as well, after the latter purchase they also used the Philips brand name a bit more). First usage of the Norelco name was on imported products, its last usage was on shavers.
They did use the Phillips name by the late 1990s. Somewhere between 2000 and 2005, I bought the last CRT TV I ever bought, and it was a Phillips. And I seem to recall seeing many things branded "Phillips/Magnavox" as well. Of course, electronics bearing these brand names are just licensed out to anonymous Chinese OEMs now.
"Philips was indeed to close of a brandname to Philco." No, no it wasn't. if any normal person got them confused they would have been a retard.... Lawyers thought it was close.. and ofcouse they needed a new Mercedes-Benz
I was in no way trying to offend you! I just interpreted "later on" as "later in the video". On topic of this video : I would never thought, explaining CD laser tracking could be actually funny. Great job! And please do more of your "no script" parts. You sound much more relaxed in those. :)
I love the titles on your channels never really think "that sounds fun", next minute I'm already watching. Great work and your vids always bring me happiness
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
Bit of a physics point here. Sucking isn't attractive and merely just creates differences in density to move a medium, not for example, a disc (easily anyway)
I've come back to these videos several times over the last few months. They're pretty neat. I never knew that CD's were actually technically analog. It does makes sense though. I knew that the golden discs on the Voyager craft were analog encodings of digital data. Anyway, long live the CD!
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.
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 ;)
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!
love the series on digital sound! I think a really interesting next step would be explaining lossless and lossy sound compression. I searched around for a video but can't find anyone that explains it as nicely as you could.
You are right on with your comment about servicing CD players. They were indeed hard to service for most "playing music errors". Mechanical errors were easier, such as loading a disc. Eventually the cost plummeted , they became a "throw away" device...like most consumer electronics devices are now. Cool video!
Excellent video. In the next one could you explain how do the CD burners and the CD-R and CD-RW work? Please. Greetings from Mexico, your channel helps me to improve my English.
To answer your "how they serviced these things" question, in the mid-80's we used test jigs on the Matsushita devices. These were Lexan shells that placed pins at test points on the PCBs. As you've observed, the designs were modular. The PCBs and mechanism were mounted to a plastic interior frame also used to mount the exterior case parts. FYI : early laser diodes didn't last *nearly* as long as later generations, the direct result being the frequent replacement of many (many) diodes and in certain cases the entire laser/lens assembly.
Hi! Just stumbled upon your channel and since im a Electromechanical Engineer... i stayed :D - Keep up the good work, very interesting topics you discuss and i like your humor :-) Cheers from Switzerland
Atleast I understood you clearly in the last video that you were going to take this topic in another video. Also people who accept their mistakes are the only ones capable of rectifying them. So kudos to you!
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.
these videos bring me life. also wildly detailed technical descriptions of nearly invisible yet utterly incredible technological accomplishments. but mostly life.
I just couldn't hold back at 18:04 "... but it's a lot harder if you're wiggling this BIG swinging thing..." yep size does indeed matter for some... lol
Look at his chin, blue reflection from the blue shirt... Great video BTW and i loved the subtle change of color, even if it was digitally composed after...
Compact Discs were amazing tech. I know SD cards and flash memory hold so much more data, but this little spinning optical technology was so complex and ingenious and perfectly executed. Vinyl is a dinosaur compared to CD, it's funny how vinyl is making a comeback while CDs are $0.50 each in bins.
Vinyl music is a complete different type of music... CDs use data, so there is very little sound and experience difference than using a flash drive... Vinyl is about the experience and the sound... since CDs use data, they have less value...
I really appreciate the videos you do - the complexity is what differentiates you from others I watch. Thanks for de-magicking these devices into such a way that makes me go - "wow that is simple and beautiful"
Awesome explanation and demonstration! For a _really_ good look at an optical system at work, check out an old gas-tube laserdisc player, such as the LD-1100 or PR-8210. It's on a huge scale compared to CD players, and the red laser lets you see it in action (with your remaining good eye.)
Oh I love this video! Real-time investigation is SO COOL! A few comments noted as I watch this... 06:00 If you have limited experience with a ‘scope, I highly recommend something simpler, like a 2-Channel TDK. A used TDS-2002 or similar would be a great learning tool. 07:25 The signal from the photodiodes is probably a current signal, which is why you see nothing with a voltage probe. You’re seeing the diode voltage, which will be fairly constant. Maybe I should watch the oscilloscope bonus episode...
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). :)
Believe it or not there are electronic repair shops that would fix it, and if it was under warranty the company would likely repair the defective unit as well.
I love you videos. I learn things I've always wondered about with each one. Keep up the good work. And I for one would love to see you go into DVD after you're finished with CD.
"And that's h...." **song cuts off** LOL, love it. I'm finding these videos extremely fascinating. Thanks so much for these videos, it's quite interesting.
Your shirt changing colors blew my mind for a second. I wasn't sure at first that it actually had happened, and I had to back it up and play that again to be sure.
Pin 10, seriously... Cool shirt though :-) That focusing system is quite clever. And reading something relatively inaccurate very accurately is now becoming history just because of faster net and cheaper semiconductor memory. Future generations will look at this in awe, finding it hard to believe that people really had to move a physical lense.
Yes, but hard drives have the advantage that they can be made mechanically very accurate, since you don't need to make the disk out of cheap plastic and insert it into the drive. Some DVD's sound like they are going to shake to bits, and yet the player can read them. That's what amazes me the most. Not to say that the mechanical accuracy and speed of hard drives isn't impressive too. People will find it hard to believe that once they were cheaper than electronic memory.
CDs are going to still be here for the next 50 or till something better comes along. Streaming sucks balls when it comes to sound quality it is worse than. mp3s
Yes, streaming quality is bad, but you can buy music as files. Also lossless and higher bitrate than CD. Buying a physical medium has become rather meaningless in digital music.
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?
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.
5:04 "There's pretty much no way to operate this when it's disassembled". Philips made an extension cable for the flex cable that you could buy via the Service Department, which made it possible to do that. I know Philips is not exactly known for easy serviceability but I repaired a Philips CD-473 from 1987 last weekend which has a board that looks remarkably similar to yours (10:04) but has DIP versions of the decoder chips TDA5708 and TDA5709 and some other changes. And the service manual says that the CD-473 was produced with the CDM2 as well as the CDM-4 mechanism soooo... I think the argument that Sony's mechanism full of chips was easier to exchange with a different one, only goes so far. Maybe it was easier for Sony engineers to make changes to the mechanism without making changes to the motherboard or vice versa, but whenever a Philips owner would need to get their entire mechanism exchanged, it would probably have been cheaper.
These videos are great! I'm not a hardware guy, so these hardware details are things that I just never encountered in my career. And yes, dig all you want into the history of DVDs.
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.
These videos are like wikipedia: topics I did not specifically search for, but then read/watch all of it anyway, because it's just the right mix of overview and detail. After that I have to follow the links to similar topics... and gone is the evening. Too bad that a lot of people will think that 20 minutes is too long and rather watch hours of cat, makeup or gaming videos. They are missing out.
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...
Excellent video. Now i have to wait until the next video is uploaded. And though i am interested in a video about how dvds work i would like know more about the format war between the HD-DVD and the Blue-ray. Anyways thanks for making another interesting video
Hey TC, love your videos. Nice to see you using the same oscilloscope as I have, the DS1054Z. I just wanted to check you know that it's easy to do an 'unofficial' upgrade to convert it to a DS1104Z. It thus becomes a 100Mhz scope rather than 50Mhz, and I there's a couple of other extra features unlocked as well (at least there were on mine back in 2015). You probably already know, but I thought I'd check to be sure. If not, the guide is on EEVBlog forum, and I'm sure Google will supply it quickly.
Some men just want to watch the world learn.
This is 20 year old technology!
My mistake, 32.5 years.
You must be new here...
Why do they make a big thing about CD.
Phillips Laser Vision came first, the forrunner of DVD.
He's got videos about that too. He teaches about all kinds of retro and modern technology.
Love how the comedy and attitude has only grown along with the increased detail and production values.
there's no less technical knowledge with increased comedy/attitude so why not? not like the information here would actually be used to aid a live project, you're better off finding datasheets and techspecs to read if that's what you really need (such as those used by this uploader to create the video)
@@memberwhen22 Someone had a sad teenager life. If you're here only for the technical knowledge as you say, may I suggest digging through Wikipedia and service manuals yourself? You'll get even more info, and faster. Let's not pretend that short form UA-cam videos are the epitome of education, their main purpose is to be entertaining and you're here to be entertained. If you disagree with that you're delusional.
@@uwirl4338 Why do you assume that a desire for information without the fluff requires a sad teenager life? I'd love to hear your metal gymnastics for that
@@maskettaman1488 now now now now now here. Wherehow the crap?
@@dickJohnsonpeter ?????
18:56 That shirt colour trickery was pretty clever.
Yes, one has to wonder if this was all planned in advance, or the idea came up in post-production ;-)
A TRUELY _COLORFUL_ idea...😉
It looks like his shirt was actually blue and the red was chroma keyed, but how was the blue square in the background set not effected?
@@HailAnts probably just masked out, he didn't move much
If you look closely, you can see that a wire in the player also changes color
Didn't think you'd see me sing, didya? Rest assured that the intro is tongue-in-cheek. You'll have to forgive me for the snark, but I really do want us to work together to make the world a better place. And communication is a big part of that.
Speaking of communication, this is a re-edit to further condense some segments of this video! Some patrons left feedback that made be realize it was all over the place (and to some extent still is). But, I couldn't cut it entirely from the video, as I said we were going to use the scope in the last one. So I'm hoping the roughly four minute segment isn't too much.
In fact, there was a *lot* of stuff that I found with the oscilloscope, far too much to fit into here. If you want to check it out, see the link in the description (and there's lot's of other good stuff in there, too). And don't forget to check out the third video on TC2!
The humor is delightful and the technical bits are informative as always, keep up the good work!
All of your videos give me a big ol' brain-boner. Could you do more on VHS?
Whoa
What was hilarious to me was when you started singing a second time and then immediately cut it off. For some reason that sort of reminds me of the sort of humor I saw in the TV series _Bill Nye the Science Guy_ that I watched when I was younger. Or maybe I'm just weird.
I loved the interlude! More!
I don't even watch most of your videos but I just wanted to say what you do is a public service to the world and your videos will be relevant and valuable for decades. I remember depending on one of your videos from years ago, just a few weeks ago. Your content is timeless, you're like a video version of wikipedia, keep up the great work and thank you so much for all the content you've already given us.
@Mike Anderson Plot twist : we are robots in a sim
*videos 😊
@@ShazeemKhanWhat?
I love the greater injection of personality. It’s been subtle, before, but it feels like you’re finding your voice, and it’s extremely entertaining.
The P at the end of an IC's model number simply means that it is in a Plastic DIP package. Since ICs can come in different forms (surface mount, ceramic, etc.) it's often useful to leave off the trailing P when searching for data sheets.
Edit: Comment deleted due to someone else stealing my stupid joke.
and the XC stands for experimental circuit Mot speak for a chip that has not passed all quals yet. after it does, it is promoted to MC (Motorola Circuit) source: worked at Mot Semi for 25 years.
Hunter Scales: In practice, it was apparently also used for custom chips (such as this mask programmed one) that were as far as I've seen never given MC numbers. I've seen my share of XC as well as ZC chips in consumer electronics. Do you by any chance know what ZC officially stands for? I vaguely remember seeing TY on some stereo decoder chips for TV as well, would have to look it up to confirm.
Just leave of any trailing letters when searching for data sheets
Love Westlife❤️
I love the balance of humor and madness and information from this channel. It kinda feels like Vsauce, where it all began very clear cut and presented professionally, and now it's professional chaos that's greater than the sum of its parts. Not only is Technology Connections informative, it's art.
This channel's contents are so in-depth, it's scary and indescribably amazing at the same time...
I hate poo poo.
love it, love this channel, this is my kinda entertainment when i'm silicon hungry. keep truckin'
this is the kind of stuff i randomly found myself reading about at 3am on random nights. awesome channel, love this stuff.
I've certainly recommended it to a lot of people. Hes more historian than engineer but his understanding is certainly improving fairly quickly over this past year or two. Either way I've been interested enough to watch almost religiously.
"I didn't know this was the Society for Pedantics!"
"It isn't. It's the Pedantry Society."
Also, the reason for the long plastic bar for the power switch being at the back as that a long plastic bar is cheaper than copper wires coming to the front, it is easier to install and less likely to be damaged with handling the player (wires need retaining and solder joints fail). Everything in consumer electronics was done for cost, hence why a single layer board when two or more layers would easily improve noise performance.
I bet it's (also) done to keep AC current as far as they can from a signal processing circuits.
@@fffUUUUUU No, the AC is easily filtered out or easily designed out. The plastic bar is purely due to cost.
It's also to keep the 240V areas of the board confined to one small area, for safety. There are rules about that sort of thing, for CE type approval, etc.
@@GRAHAMAUS This is the actual answer. Separating mains circuits from low(er)-voltage circuits is serious business. You won't get FCC (and UL, and TUV, and so on) approval otherwise.
Dude I'm always impressed how super complicated things we take for granted are.
Lets take a moment to appreciate the amount of time, effort and devotion this guy puts into his work!
The red to blue tshirt color change is the most convincing special effect in all of cinema of 2018.
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.
18:17 Thank you for using the international symbol for "CD Walkman"
Tom scott reference?
Computer engineering student here, I learn about eletronics on my course, but because the focus isn't eletronics, I can't give you a very technical explanation.
But when you tried to read the waveform from the diode, the problem was the way you set-up the oscilloscope and how circuits are designed.
So I don't know how to begin to explain, but here it goes.
The main problem is the noise, when you set up the osciloscope to DC coupling, the ground cable is the reference one and depending on where you plug it, this reference can be differente from circuito to circuit, so the first step I would do(I coun't see this in your case) is to use the ground pin from the IC and not the general one. This happens a lot in circuit design, because a lot of devices causes noise, you need to fix this when you are designing it and the easiest way is to make the VCC and GND to go along with the noise(simillar how XLR sound works), eliminating the noise and making that the circuit aways have the same electric potential.
Another problem is eletrical things near the oscilloscope probres, where the cable is affected by near eletric fields(the raspberry pi 3 POE hat video from eev-blog, show this happening) and can be reduced by changing the path of the probes.
A bad way to handle this is when working with digital signals that have a lot of pulses(PWM or similar) is to change the coupling from DC to AC. This is a bad way because when you do this you can't decode the signal and see if the circuit is working fine. But works.
The best way to handle this, is to don't let any cable near the probres and keep them straight. If this isn't possible, the best way is to buy some low noise probres or callibrate the oscilloscope with the noise.
Mostly right. I just wanted to point out that if the device has an isolated power supply you could hook up the osc. probes across any two points. A rule of thumb is that it's never isolated so this feature of oscilloscopes is just a tease and conspiracy to sell fuses ;) Sometimes battery powered devices are isolated, as long as they aren't plugged into anything through USB or other shielded cables.
Generally the only safe way to use an oscilloscope is to keep the ground clip on the correct ground (even this can get tricky). Just think of the oscilloscope's ground clip always being connected to earth ground and it makes a bit more sense that poking a circuit with that at random could short things out.
[Edit] Hooking up the ground clip to a chip's ground could theoretically reduce noise, but odds are that chip is surface mount and the only way to hook it up is soldering an enameled wire to it, which then picks up noise and defeats the purpose. Plus, everything I said about hooking up to the 'correct' ground can make this impossible unless the device is isolated.
The photo diode signals from the Philips OPU are currents not voltages so they feed a virtual short circuit in the chip downstream so you should only see voltage noise there. . In Japanese OPUs the signal is a voltage.
I designed a circuit to convert from the voltages back to currents while working for Philips Semiconductors to let Japanese OPUs work wiith Philips chips.
@@mikedjames oh, is that why modern sigma delta semiconductors that are mostly voltage usually have a I/V stage that then feeds a lpf to the output stage?
AKM made an all current output delta sigma chip back in 2019 the AK4499. Supposedly it was the first ever made. Then they had a fire now the redesigned into a 2 stage chip set. One chip decodes the digtal and the other the analog output to cut down on crossfeed (in theory)
It seems like Philips current semiconductor was the better approach with no conversion??
@@joesmith4443 you can either have a voltage source i.e. a hard switching transistor pair fed from a good solid supply - basically a standard logic inverter off the shelf, in a digital IC..
or a matched pair of current sources where the P and N transistors have to be accurately sized, i.e. an analog IC.
When AKM went 2 chips that was because the digital IC process was shrunk so uses smaller geometry rules for cost and availability, while the analog part has to stay about the same size geometry for noise reasons ( digital chips can operate with so few electrons, analog needs more as each electron is a quantum of charge or a step in the voltage or current so you need to use many more to average out and get SNR to CD player levels - theres a limit with the current..) . and therefore use an older IC process..
The Philips servos also used a sigma- delta ADC , it had the advantage of having tracking frequency response up to about 1MHZ for large changes in the differential part of the loop, then filtered down in the integrator to a fewkHZ for the integral part of the loop..
As the detectors are photodiodes, it was easier to feed current in .. And the great thing about the Philips single beam tracking was it does not need to have the other adjacent tracks at the correct pitch spacing or even be present, so it could play better over dropout on the disc. But Japan wanted three beam tracking because must be better than single beam.. actually Philips used 4 photodiodes in a cross shape watching focus using astigmatism tricks, and tracking the spot in one go. So they could have called it 4 beam.
@@mikedjames oh I get it to a 2 chip system prevents thermal issues and since the “tasks” are broken down into two stage and because the analog stage can’t be smaller they can work independently without any overheating.
(Hmmm, On a slightly off topic subject I am curious how Apple uses that new gigantic M2 Pro semiconductor chip for their new Macs. To me it just seems it better to break up the CPUs or break them up into different tasks like a TPU and GPU, etc)
Yea supposedly Philips also made better noise shaping dithering modulators than Sony. I know this sort of stuff is above my knowledge but can’t one day the analog part benefit from Quantum computing. Or can “Qubits” benefit from a 1 bit simulator? Like a DSD PWM?
Also why in most DAC chips datasheets they use either fully differential op amps or a single supply op amps in the I/V to Lpf and in the wild you see more dual op amps most implementation I “get” that having a dual Op amp prevent large swings but in just about EVERY older DAC chip like the Burr Browns, Analog Devices and Cirrus Logic they used single supply op amps and in most ADC they use fully differential op amps in the datasheets. Also the the non to inverted stuff is baffling? I get what it means but why would you want to invert the signal anyway? Does this cause phasing issues?
All I know about those P and N transistors is that the discreet ones are more of challenge to match like R2R Topology “bits” but again like any chip solid state op amps makes this easier since the “gates” and resistors are well measured and guaranteed performance however some believe they don’t sound as good even if they have ultra low distortion and noise like the “3D Sound.” I just think that can been “made up” in a well designed power supply. The 3D sound is the one part that’s hard to master In Audio (I think). The Multibit chips of the past really did do a better job even if their resolution and specs are inferior to todays dac chips. However with Better resistors and computer algorithms I suspect that they chips would perform well above what they first measured in the 80s! Idk the DSP are good for certain things but for that 3D effects it’s all about hardware enigeering
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.
The intro is just pure gold!
Excellent video! I really like your honesty in posting parts where you're poking around and making discoveries instead of trying to make the whole video look intentional. Keep up the great work!
Thank you soo much for not putting an apostrophe into CDs! ❤
Haha I hate it when UA-camr's do it
One of my little bugaboo's in life is how people misuse apostrophe's.
Stylistic preferences are for 0s.
The King of Poland it’s a disastrophe
The only acceptable (albeit probably wrong) use of apostrophes for plurals is when the word is fully lowercase acronym
Philips was indeed to close of a brandname to Philco. For lighting products, and cassette tapes they used the Norelco name.
The clicking noise when slowing down the disc by hand is the laser freaking out and swinging into its end stops.
And about that service thing, Philips had extension cables to rest the CD drive aside of the main PCB.
The Norelco name was afaik slowly phased out after they purchased Magnavox (and later Sylvania and Philco as well, after the latter purchase they also used the Philips brand name a bit more). First usage of the Norelco name was on imported products, its last usage was on shavers.
They did use the Phillips name by the late 1990s. Somewhere between 2000 and 2005, I bought the last CRT TV I ever bought, and it was a Phillips. And I seem to recall seeing many things branded "Phillips/Magnavox" as well. Of course, electronics bearing these brand names are just licensed out to anonymous Chinese OEMs now.
"Philips was indeed to close of a brandname to Philco." No, no it wasn't. if any normal person got them confused they would have been a retard.... Lawyers thought it was close.. and ofcouse they needed a new Mercedes-Benz
@@DanafoxyVixen so lawyers must be retarded. ;0)
I was in no way trying to offend you! I just interpreted "later on" as "later in the video".
On topic of this video : I would never thought, explaining CD laser tracking could be actually funny. Great job!
And please do more of your "no script" parts. You sound much more relaxed in those. :)
Could have stood up for yourself.
Instead you melted and complimented him?!
@@CableWrestler what's wrong with this civil display?
@@Srcsqwrn hes kidding
@@wompwomp1658 Bad joke then.
@@Srcsqwrn eh could be your sense of humor sucks, I found it funny
I love the titles on your channels never really think "that sounds fun", next minute I'm already watching.
Great work and your vids always bring me happiness
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
Could we see the insides of a player that doesn't have a external tray but rather sucks in the disc?
Anthony Estremera s u c c
Actually you can't as they have metal all around. It's just a metal box with the disc loading slit in front and a ribbon cable under it.
@@konatadesuka sounds like Fort Knox
Bit of a physics point here. Sucking isn't attractive and merely just creates differences in density to move a medium, not for example, a disc (easily anyway)
If you are still interested, there are quite a lot of PS4 disc tray fix videos that show the internal mechanism
I've come back to these videos several times over the last few months. They're pretty neat. I never knew that CD's were actually technically analog. It does makes sense though. I knew that the golden discs on the Voyager craft were analog encodings of digital data. Anyway, long live the CD!
Are you that lonely !?
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.
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 ;)
As someone who grew up with a learning disability; I thank you for these educational videos. 🙏
Fantastic! Reminds me of the CD theory and servicing course I did way back in '88
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!
My interest definitely persists and I really appreciate your videos and delivery. Well done on building such a great channel in such a short time.
love the series on digital sound! I think a really interesting next step would be explaining lossless and lossy sound compression. I searched around for a video but can't find anyone that explains it as nicely as you could.
I freaking love this channel, you're doing a great job, mate.
I just like this guy. So informative and entertaining. Time just flies when you're having fun.
Amazing video! So in depth and at the same time entertaining and clear, big Kudos!
You are right on with your comment about servicing CD players. They were indeed hard to service for most "playing music errors". Mechanical errors were easier, such as loading a disc. Eventually the cost plummeted , they became a "throw away" device...like most consumer electronics devices are now. Cool video!
Excellent video. In the next one could you explain how do the CD burners and the CD-R and CD-RW work? Please. Greetings from Mexico, your channel helps me to improve my English.
To answer your "how they serviced these things" question, in the mid-80's we used test jigs on the Matsushita devices. These were Lexan shells that placed pins at test points on the PCBs. As you've observed, the designs were modular. The PCBs and mechanism were mounted to a plastic interior frame also used to mount the exterior case parts. FYI : early laser diodes didn't last *nearly* as long as later generations, the direct result being the frequent replacement of many (many) diodes and in certain cases the entire laser/lens assembly.
Incredible work as always. Can't wait to see more.
Hi! Just stumbled upon your channel and since im a Electromechanical Engineer... i stayed :D - Keep up the good work, very interesting topics you discuss and i like your humor :-) Cheers from Switzerland
Atleast I understood you clearly in the last video that you were going to take this topic in another video.
Also people who accept their mistakes are the only ones capable of rectifying them.
So kudos to you!
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.
these videos bring me life. also wildly detailed technical descriptions of nearly invisible yet utterly incredible technological accomplishments. but mostly life.
19:02 I see what you did there... I c u
VERY smoooooth!! 🙂
I just couldn't hold back at 18:04 "... but it's a lot harder if you're wiggling this BIG swinging thing..." yep size does indeed matter for some... lol
Look at his chin, blue reflection from the blue shirt... Great video BTW and i loved the subtle change of color, even if it was digitally composed after...
Compact Discs were amazing tech. I know SD cards and flash memory hold so much more data, but this little spinning optical technology was so complex and ingenious and perfectly executed. Vinyl is a dinosaur compared to CD, it's funny how vinyl is making a comeback while CDs are $0.50 each in bins.
And now CD is making a comeback too
Vinyl music is a complete different type of music... CDs use data, so there is very little sound and experience difference than using a flash drive...
Vinyl is about the experience and the sound... since CDs use data, they have less value...
I really appreciate the videos you do - the complexity is what differentiates you from others I watch. Thanks for de-magicking these devices into such a way that makes me go - "wow that is simple and beautiful"
Do DVDs!
This is just marvelous. The amount of knowledge conveyed is enormous and it is easy to follow and actually understand.
Awesome explanation and demonstration!
For a _really_ good look at an optical system at work, check out an old gas-tube laserdisc player, such as the LD-1100 or PR-8210. It's on a huge scale compared to CD players, and the red laser lets you see it in action (with your remaining good eye.)
Oh I love this video! Real-time investigation is SO COOL! A few comments noted as I watch this...
06:00 If you have limited experience with a ‘scope, I highly recommend something simpler, like a 2-Channel TDK. A used TDS-2002 or similar would be a great learning tool.
07:25 The signal from the photodiodes is probably a current signal, which is why you see nothing with a voltage probe. You’re seeing the diode voltage, which will be fairly constant.
Maybe I should watch the oscilloscope bonus episode...
Thanks so much for a great video. Yes, please do continue this series!
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). :)
Hi, great channel! I have a burning question: how do the tracking and focus mechanisms work during a burning operation? Thank you.
These videos are getting better and better, and people think I'm weird for not watching TV.
Oh yes. Id much rather watch crappy scripted reality shows
America's talent idol got the Voice
Tv sucks.
Nice motorized slider shots :-)
You improved the video quality so much lately 👍
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.
"I don't know how people would service these things"
They don't. It's an electronics. You are expected to buy a new one.
12:46
My new favorite line.
Believe it or not there are electronic repair shops that would fix it, and if it was under warranty the company would likely repair the defective unit as well.
Most of the technical stuff is way over my head, so I'm just here for the jokes. The sarcasm is strong with this one!
I love you videos. I learn things I've always wondered about with each one. Keep up the good work. And I for one would love to see you go into DVD after you're finished with CD.
Your videos are great!!!! I love old school formats. I would love to see you also do one on the minidisc...
"And that's h...." **song cuts off** LOL, love it. I'm finding these videos extremely fascinating. Thanks so much for these videos, it's quite interesting.
At least Philips didn't put Malware onto their music CD's ...
Yeah, that was a good thing.
I’m just glad they didn’t put seafood onto them either, as I am allergic.
It’s sad, but it’s understandable.
@@Gabito04
not its not .. stupid
Laser Beam ...that’s a reply for Matthew... but yeah, putting malware on CDs are clearly dumb.
Your shirt changing colors blew my mind for a second. I wasn't sure at first that it actually had happened, and I had to back it up and play that again to be sure.
This is such a great channel I love knowing how things work and you explain things so well and make me laugh.
Pin 10, seriously... Cool shirt though :-) That focusing system is quite clever. And reading something relatively inaccurate very accurately is now becoming history just because of faster net and cheaper semiconductor memory. Future generations will look at this in awe, finding it hard to believe that people really had to move a physical lense.
Yes, but hard drives have the advantage that they can be made mechanically very accurate, since you don't need to make the disk out of cheap plastic and insert it into the drive. Some DVD's sound like they are going to shake to bits, and yet the player can read them. That's what amazes me the most. Not to say that the mechanical accuracy and speed of hard drives isn't impressive too. People will find it hard to believe that once they were cheaper than electronic memory.
CDs are going to still be here for the next 50 or till something better comes along. Streaming sucks balls when it comes to sound quality it is worse than. mp3s
Yes, streaming quality is bad, but you can buy music as files. Also lossless and higher bitrate than CD. Buying a physical medium has become rather meaningless in digital music.
@@esa062 there is no digital format better than a cd.
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?
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.
You get better with every single video I watch here! :D Prestine editing here! Thanks!
Why does this channel get SO less views
yes, the video is uploaded 30 minutes ago, but the view count is under 1000 !
Because it's not a "My cat does my makeup while I eat a bowl of gross food" type of video.
Because as intelligence increases, views decrease. Put another way, most people literally hate to use their brains.
Few. So *few* views.
@@js0137 deliberately so. It's was entirely sarcastic.
5:04 "There's pretty much no way to operate this when it's disassembled". Philips made an extension cable for the flex cable that you could buy via the Service Department, which made it possible to do that.
I know Philips is not exactly known for easy serviceability but I repaired a Philips CD-473 from 1987 last weekend which has a board that looks remarkably similar to yours (10:04) but has DIP versions of the decoder chips TDA5708 and TDA5709 and some other changes. And the service manual says that the CD-473 was produced with the CDM2 as well as the CDM-4 mechanism soooo... I think the argument that Sony's mechanism full of chips was easier to exchange with a different one, only goes so far. Maybe it was easier for Sony engineers to make changes to the mechanism without making changes to the motherboard or vice versa, but whenever a Philips owner would need to get their entire mechanism exchanged, it would probably have been cheaper.
The Sony player shown, is 4 years newer. That would probably also account for the larger scale of integration.
Thank you again for another great video, As a fellow IL (Central) I really do appreciate the amount of sarcasm and dry wit!
These videos are great! I'm not a hardware guy, so these hardware details are things that I just never encountered in my career. And yes, dig all you want into the history of DVDs.
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.
These videos are like wikipedia: topics I did not specifically search for, but then read/watch all of it anyway, because it's just the right mix of overview and detail. After that I have to follow the links to similar topics... and gone is the evening. Too bad that a lot of people will think that 20 minutes is too long and rather watch hours of cat, makeup or gaming videos. They are missing out.
Look at that, another quality video that I enjoyed watching. Nicely done.
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!
You sure were silly today. I rather enjoyed it. And the information is still as good as always.
Most epic 21 minutes since Pink Floyd's "Echoes"
Great video learned a lot this technology is amazing when it's working but very hard to diagnose problems with specialist test rigs.
Enjoying this series very much. Please continue on through to the DVD, Blueray, and beyond!
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 still make CDs to this day
Thank you so much for doing real captions!
Dude! I love your videos! Can't wait for more!!!!
You told em Alec. Observant these UA-cam viewers are not.
One of the first 1,000 viewers!!!!
That Sony CDP-C225 was our family's first CD player and it was a fantastic one, at that!
Absolutely love the channel and videos :)
I have to say I love your content. I find myself binge watching it
Instead of a rack and pinion, some CD players use a screw drive.
I'm guilty, because i do like more your sarcasm than the content, but i do like the content, lol
I absolutely love your videos! Bargaining with the audience xD you have such a positive outlook on life
This is very educational and I'm also interested in old technology glad I found and subscribed this channel keep up the awesome work
I love this channel more with each video!
Love the videos! Keep them coming!
Excellent video. Now i have to wait until the next video is uploaded. And though i am interested in a video about how dvds work i would like know more about the format war between the HD-DVD and the Blue-ray. Anyways thanks for making another interesting video
Hey TC, love your videos. Nice to see you using the same oscilloscope as I have, the DS1054Z. I just wanted to check you know that it's easy to do an 'unofficial' upgrade to convert it to a DS1104Z. It thus becomes a 100Mhz scope rather than 50Mhz, and I there's a couple of other extra features unlocked as well (at least there were on mine back in 2015). You probably already know, but I thought I'd check to be sure. If not, the guide is on EEVBlog forum, and I'm sure Google will supply it quickly.
Oh! Cannot wait to see stuff on writable discs, I so much have always wondered how they worked.
well done, thanking you for presenting such informative videos
Now I'm wondering about the secrets hidden in the subcodes in all my old discs. Thanks for the series, and I enjoyed the off the cuff section.
Love your dry humor and self reflection