Take a cassette out of its case and most people just see an empty box. but Sony saw something quite different. Sony introduces the only cassette player as small as a cassette case, the incredible sounding Super Walkman. Okay, so we don't quite have one the size of a cassette tape, but we have the ultimate Sony Walkman Check it out.

This is the original Sony TP SL 2 Walkman Originally released in 1979. Awesome. This is the one that started all. Thank you very much to Rowland and Max who sent this in to the mailbag.

So let's do a retro teardown. It doesn't get any better than this. Originally released in 1979 in Japan It didn't hit the US until 1980 in that it was called the Sound About apparently. but geez, everyone knows it as the Walkman and this assured in a cultural revolution.

Personal Music I Mean people take you know their phones or their all the iPod for granted or whatever. but this thing defined personal music. It changed everything and Sony dominated the field with the the personal music field with the Sony Walkman For decades, originally released at 150 dollars, That's four hundred and eighty-eight bucks in today's money, so you know it wasn't a cheap item. But geez, it was a revolution.

It really was. You can take your personal cassette whack it in. You can actually listen to music as you walked about, hence the name Walkman Apparently they didn't like the original name Walkman but it kind of stuck and it was too difficult to change the marketing on it apparently. So yeah, they were stuck with Walkman.

Now this was designed by Sony's famous designer, Nobatoshi, Kihara and I mentioned him in a previous Sony video that I did. He was not only instrumental in the Walkman here, but in a most everything else in the Sony lineup. And yeah, and he was famous for designing these things Super quick. like getting prototypes up and running.

super quick to show to management. Management had the idea oh I want Well, the young Sony CEO or the president at the time or vice president or whoever it was says I want to listen to music on my plane trip So Nobatoshi went to the lab and whipped up the Sony Walkman Ah, it's a thing of beauty. Look at this. Ah, a couple of Double A's no worries and people both inside and outside of Sony said this thing will never ever sell if it doesn't have a recording function and you'll see it doesn't play rewind fast-forward stop and that's it.

Yes, it has a microphone, but that was for the dual headphone feature and this rather unusual hotline function here, which allowed you to talk to the other person who was tethered one meter away from you. Hmm, don't quite get it. Yes, it was stereo. Look at this.

I Absolutely beautiful. You can change the individual volume on the left and right channels and now this graphic equalizer. Rubbish. Look at this stunning feature.

your high pass filter tone high and low. Thank you very much for those playing along at home. This is a reasonably low serial number considering that they eventually sell 389 million. Walkman So obviously not this TPS L2 original TPS L2 model.

but anyway. 60 1954 You know we say here on the Eevblog don't turn it on, take it apart. So let's take this classic thing apart. I've got no idea how it comes apart.

We'll have to just wing it. and I don't expect to find any surface mount parts in this matter. Oh 1979 Oh yeah, I doubt it'll all be a classic through-hole stuff. There'll be no processing at all.

This thing didn't have a built-in radio so you don't way have to worry about you know, having a big a ferrite rot in there and all the miscellaneous stuff that went along with having that aha, this one just came off and ah, we're in like Flynn look at that. Well not quite in like Flynn yet. but well, yeah, that just reeks of 1979, doesn't it? Let me smell it? Oh yeah, definitely 1979 way maybe it was manufacturing 1980. My smell is usually a bit, you know, like a plus minus one year accuracy on it.

but yeah, well got ourselves a little La trimmer there I wonder what that puppy is for? Hmm. tape bias or something like that, perhaps. And here we go. I got the shell.

a couple of little tiny Phillips in there and that Oh she'll just lifts off but it is attached via oops that join up while we're in. Oh look at that. We can see the rollers. Look at that still intact.

And for you young whippersnappers, you don't know how cassette player works. Well, Here it is. It's basically a mechanical mechanism for the head. Here's our red head.

Note that this is not a record, doesn't have the recording function, so this is not a recording head. So this whole plate. once you put your cassette down in here, then it pushes the head in and locks in place against the tape, which of course goes from one reel to the other. It wraps around here goes through this up.

Pinch roller here. You'll notice that rubber roller goes onto that post there and that just pinches and that takes up the slack on the tape. There's usually an inertial roller here as well, but to help sort of, you know, keep the tape nice and tight. But that one.

But this particular model doesn't have an inertial roller here. It's only got the pinch roller there anyway. There's a motor drive in here and that just rotates of course and the tape just loops from the supply rail here to the take-up reel and then just goes around and around like that. And of course, if you want to rewind or fast-forward you all know that something's switching in there.

You can see something switch, but that just of course disengages the head because you don't want to drag the tape at high speed across the head when you fast forward or rewind in. and that just, um, it drives the motors in here to put the tape wherever you want. And no, this one's not the fancy pantsy auto reverse mechanism that came along in. Jeez! I don't know was did we get mid 80s before we got Auto reversing mechanisms where the head would flip around and oh jeez, that was the Ducks guts and then came I am stereo and then we've got the super advanced ejection mechanism here.

if it's in the play mode, you press it once, it'll disengage the play mode and then whoohoo just flips it out like that. Oh Bob's your uncle Now let's check out the guts of it here. And the interesting thing to note about this: We'll look at the electronics in a minute, but I'm more interested in the mechanics of this thing and they've done outlook a good job to really pack this in here. Absolutely amazing.

And here's our motor down in here. There we go and that is that drives everything. Joys: the play mechanism, the forward and reverse mechanism as well. so it doesn't have a direct drive motor under these like you got in future ones.

Of course it all does everything with the one built. Look at this rubber belt here. it's still intact, but it's loosey-goosey That's why this one doesn't work if I play this thing, then there's not enough fart tension in that belt to actually do anything. Look I've got batteries in this thing and I can play it and probably can't see that.

but I can assure I can feel that motor moving but it's just yet. it's not taking up that rubber built there so it's a little bit loosey-goosey Can't see much from this angle, but it must, uh, engage the rollers differently and we press play. You'll notice that as we press play, that rubber pinch roller down there actually engages this cog here and boom it. That's what muster drive the play mechanism.

Unfortunately, the belt is loosey-goosey but you could probably yeah, service this thing and get it back into operational shape. but yet no direct drive motor. rubbish. This was all just single modal with belts and police love it.

Check out this old-school through-hole Led. Oh my goodness, that's hilarious Leo, that still works! What a Bobby Dazzler And the main PCB here looks like it's a single sided job through all through all as I said. but I'm surprised the amount of jumper wires going all around here. but why didn't they spring for a double-sided board? Well too expensive for a consumer product? I Guess they you know it was cheaper to have someone you know do the manual labor and add all these little jumper wires all over the shop.

Here you know you got to get from one side of the board to the other. Geez. I Wonder if they could have optimized their art? Single sided layout? I Don't think Nobatoshi himself would have done this layout Anyway, they got some tape holding all this down and these probably run off to another board under there. Perhaps would have to take that off.

but your man, totally 1970s written all over it. and up here we've got genuine budge resistors. or are they were? they actually part of the design. couldn't fit them on the top? err.

let's just whack them on the bottom. No worry, she'll be right. We got ourselves a nice little custom transformer. there.

Just a couple of turns on each side and it's nicely heat shrunk. Actually, that is like purposely designed. They've actually put cutouts like little slot cutouts in the bore where the wires go down for that thing and then they've wired it over to the top here. Wow Someone was thinking, check out the copper shielding tape around the back of the head here.

Got to keep that noise out so we'd have a shielded coax going over there from the head and you can see our volume controls. They're just carbon sliders on the what is that? Just like a bakelite er back in or something like that, you know. Very crude. I Think very typical 1970s.

These things weren't built to last. Really though, it you know, built down our price to get the job done and to get this apart anymore is really troublesome enough. 2d solder all the wires and some like sort of like crimped in place over here be a real pain. So I don't want to do that I Want to put this back in its original condition.

We can see all the rollers down here. Now here's the main motor drive. As I said, it's got a single built which goes around this roller here and around this big flywheel here. Okay so that's the main wheel and then let's actually engage, engage play there.

We can see with that play that pinch wheel in there engages this cog down in here which is the main drive for the take-up wheel here. Now if we stop that and we put that in Reverse you'll see that this cog flip over and then it can. The pinch wheel here will then drive the reverse the other spindle here which of course are causes the mechanism to go backwards or via. here.

it could actually be yeah it's in that one so that engages that and that's what puts it in up. That's what puts it into reverse. So if we put that into play mode you'll also see this pinch roller come across here like this and then that's engaging that the main spindle over there like that. So this belt is coming.

so it's getting its drive from this main belt coming over here like this and then that's engaging that. through these cogs down to this pinch wheel and then that's going over to this to the main method. the main spindle there, the main, our take-up spindle. So if you put that in dryer, if you put that in forward though, you'll notice that there we go, you'll notice that this pinch wheel didn't engage so it's no longer driving the take-up wheel here.

The take-up wheel is being driven through this pinch roller here, through off the main spin to the bottom part of this main spindle here. So it's going to be turning a lot faster than the built up the top in play mode. and then that's going through here, engaging these cogs and bingo it driving the COG down there. So our take-up wheel is obviously going to move faster because we're in fast-forward mode and of course future cassette decks are overcame all these you know, mechanical pulleys and everything else and belts and all the rest of it and cogs by using direct driver motors on the things.

That was just much easier. much but that was you know, like a decade later or something. So again, from a top view here, motor dries through this belt here in this roller to take up the slack. There dries this main pulley up.

Here you put it in play mode. This pinch wheel moves across and engages the main spindle here through this slower belt drive which is on top here and that drives it at the slow speed required for play mode. If you put it in fast-forward mode, you'll see this little cog move across here and you'll notice that the pinch roller didn't move at all. So it's not driving that driving it through the faster cog in there like that.

So we'll go at a higher speed. It's no longer being driven by this belt here. And our main board. Woohoo! Advanced Technology Single Inline I Sees here.

these are probably transistor arrays. Most likely they're not anything digital, of course, and they're I'm not, probably not. Oh, there might be some, you know, operational amplifier type functionality in there, but basically, yeah, this is essentially all discrete transistor solution. They've got a couple of extra trainees up the top there just because.

Well, they couldn't fit them into this single inline arrays. I guess or they were. You know, just better served by having discrete transistors there. We've got some Martin alums here, or these tag these dipped tag tantalum zu boogaloo.

They send a shiver up the spine. They really do. Anyone who's used to old boards like this knows all about tag. Ten alums.

Wonderfully reliable. and yeah, there we go. of course. Sony, um, rolled all their own well.

ASIC it's a transistor array I'm sure good luck getting data on that. You could win the internet. If you actually find a datasheet for one of these puppies, good luck. Mmm.

and it looks like I Win the internet folks because here is the service manual for the TPS L2. Can you believe it? Fantastic! This is in from our free service manuals dot info: I'll provide a link in down below for those playing along at home and uh hi, They don't make service manuals like this anymore. Just get a gander at this puppy. Fantastic! I Look at this specs Frequency response forty Hertz to twelve kilohertz.

Can you believe it? For track two channels stereo I Want a Bobby Dazzler Really is? Um, look approx Continuous playback hours 2.5 hours with Sony super batteries they would be you know, like carbon zinc type ones and or Eveready heavy-duty 3 point 5 volts Wow Alkaline. Eight hours with Alkaline. Unbelievable. Weighs a minuscule 390 grams.

Fantastic. And look, we get straight into the good stuff. Here's the block diagrams. hi check it out.

Here's the playback head. This is like a left channel. They're not showing the other channel. We'll see that later.

There's that stupid hotline thing with the microphone. Anyway, go straight in. Opry preamp with automatic gain control. There's our high low tone bypass thing.

Once again, it's just an RC filled up Fantastic! God Love it. And then your arm a buffer amp from the output of that and that this goes into your headphone amps and well, that's it. Bob's your uncle and of course. Well, we've got ourselves a servo amp with the motor drive here because if you didn't have this servo loop in here, while the motor could just do anything a down more likes with the battery voltage, it might not sound like Mickey Mouse like this: Hey Mickey Oh Mickey You're so fine.

You're so fine you blow my mind. Hey Mickey, Hey Mickey! So that servo amplifier just keeps the motor running at a constant speed regardless of the battery voltage and the tension on the belt and everything else. So you get a constant playback, you don't sound like Mickey and I Geez, look at this. They just don't make service manuals like this anymore.

Wow Check it out this photos of theirs if you if I was I'm probably not writing exactly how all those pulleys and everything worked and the spindles and all that sort of stuff for each Do. There you go. You've got all the details in there. There's a reverse wheel, there's the flywheel, the friction gear.

Oh man. Fantastic stuff. They tell you how it all works and if we keep going, if we keep going, keep going. There's all the pinch roller stuff for higher.

Now we get into the electrical adjustments and here is that the servo amplifier board that we just talked about. That's the RV 601. They're actually adjust the tape speed on the thing and it tells you how to do the test. There you go.

you get a three Kilohertz test tape. You whack a frequency counter into the headphone output and you need to be within plus minus 2% of the nominal 3 kilohertz. Fantastic stuff and I Love the overlays that they've got on the boards here. You'll see some of this more in a minute, but I hi, he is the money shot.

Here's the schematic and we've actually got two distinctly different schematics here and depends on the serial number. Look at this. This is the ones up to for the US serial numbers up to one hundred and six thousand. So possibly this is the one that we're looking at here.

And here's the two discreet external transistors here. Q 101 these are armed. It'll have the data. I'll tell you what.

there it is, the two SC 1363 there and you'll notice that the the here's your left and right. Our tape heads down here, which is just a basically a coil of wire on a little broken nut toroid there with a gap in it and that's what reads the magnetic information on the tape. So I'm going to left and right heads. forget about this stupid hotline function.

They basically get sent in single ended. Of course they get AC coupled and fed straight into the amplifier ASIC here IC 101 which contains an amp. Then it's got a differential amplifier, has got an output buffer, and it's got some 8a automatic gain control stuff as well. and of course duplicate circuitry for the left and the right channel.

But you notice that yet? There was no input transistor amplifier here. It just goes straight into the IC and then we've got an output for. It's a common emitter circuit here because our output is tapped off our emitter here for a low impedance. a comedy middle would be used.

It has a low impedance output, that's why it's used as a buffer like that are basically a follower and then it goes into our power amplifier and ripple filter as well. We don't any ripple in your headphones, no siree. Bob But if we go down here I'll come back to these. These are fantastic.

We've go down to this: This is for serial numbers one hundred and six thousand and later, so this doesn't look like it's ours. But look now they've got an input, a discrete transistor amplifier on the input, and that's a 2 SC 24 58. And if we go and have a look at the 2 SC 24 58 why have they got it? Well, probably because they wanted lower noise. It's designed for low noise audio amplifications.

I Don't think they did it, just purely for gain reasons. I Suspect it might be yard noise. you know, issues? Maybe there was too high noise. They wanted a bit higher performance, better noise performance out of there out of the units.

So they decided to change the circuit at a discrete transistor amplifier on the front end here before it goes into the ASIC and then they've decided. Well, we don't need our output transistor. You meet a follower here. We can just bug that straight in through our volume pot here.

Now volume pot straight into our our output amplifier. So it's a like our power amp here is a CX 1/8 for let's see, it's the same I haven't checked this. CX + CX 184. Yeah, it's exactly the same I see here.

So you've got to wonder why they needed the emitter follower buffer here after the volume control. Yet in the next edition, the more recent serial numbers, they didn't need that. It's rather strange, and these schematics really are the Ducks Cus. Look at this: DC bias voltages here so you could go in there and troubleshoot these.

The golden rule of troubleshooting thou shalt measure voltages C Go in there and you know you'd measure all your DC bias levels to make sure everything's hunky-dory And here's our servo and board. and I Found our little La Tyroid over here. That little one that had like four turns. three or four turns per side.

That side directly interface into the motor right here. And of course you've got to have a thermistor there. it is THP 601 in. They're all old-school stuff.

Got to have a thermistor beautifully. Not survey loops. just keeps them nice and under control. And we even get our LED that we saw that through-hole one.

It's a Teal r109. Anyone want to find datasheet on that? Oh thank you very much. There it is. Look at this from: Toshiba The resin stem type LED can easily mounted if drill a hole in the PCB panel.

well. Sony Dayton Didn't bother with that, they had to bend it over and have its asked flapping in the breeze. These service manuals really are just gorgeous. Look at these: I Love these transparent overlay board wiring diagrams.

Fantastic stuff. Look at this and you know John that somebody's gone in there and drawn all this. You know these are all like this is all like hand drafted stuff. This is fantastic.

Nice. New Age CAD Stuff This is absolutely brilliant stuff. I Love it. If that wasn't enough to blow your mind, then these exploded views will aah-ha-aah Thank you very much.

And then for our happy ending. Of course we've got a full comprehensive parts list. Ah, Just Beautiful brings a tear to the eye. Geez, look even the screws specified.

But hold on to your hats folks! We've got our service bulletin here and this is where we do some noise. The symptom looks: static noise is heard in the right channel Airport of Remedy. Replace the middle puller assembly, the four idler assembly, blah blah blah blah blah And it. What do we have to do? I Don't know.

Find the shielded paper. There we go. We've got to add in some a copper shielding tape. Ah Beautiful! The shield kit is a large sheet of copper enough for 200 modifications.

There you go, you've got to trim it to exactly this. Absolutely, bro. And then you've got to be very careful where to fold it over the conductor side. Like this, this area is rather critical.

Do not oversize or undersized the copper sheet. Ah, terrific stuff. And you can actually see the servo feedback here inside the motor. So they've got a drive and the feedback which goes into our servo controller board under here.

I Won't bother taking that out. Nothing terribly interesting in there. so there you go. I Hope you enjoyed that look inside This original game-changing Sony walkman.

the TP SL 2 and this models actually the original one doesn't even have the Walkman branding on here. They did actually change that on later serial numbers. So yeah, this is one of the original ones. Fantastic! So this really was very advanced stuff rats day.

and there's not much wasted space inside this thing either. Oh, there's like always all through-hole That's like the best they could do back then and they wedged it all in. There's not much like actual volume wasted. It really is quite nice how they've done it all.

Quite a comp. I'm very surprised by the complexity of the drive mechanism. actually expected something a little bit simpler than that. If you open up you know, in a few years, a couple of models ahead of this one, you'll notice that it's probably greatly simplified from this.

but this was designed in 1978 by a nobatoshi Chiara the famous Sony design who sadly no longer with us and he did a fantastic job on this. And of course it's not wasn't just him, it was all the countless engineers who would have worked to get the final thing through to production. and well, they a lot of people didn't think it would be a wildly successful, but it was more than just a sales success. It was a complete cultural revolution.

It started the portable music scene, which was everything back in the 80s. It was no internet kiddies, there were no mobile phones, there were no smartphones. it was. That's it.

You could take your music with you haha. mind-blowing so thank you very much Rowling and Max for sending in. a quite rare these days they do Cofer Quite a bit of money on E-bay they're highly sought up. Errant Li was used in some sci-fi movie I don't know about anyway.

people will be jumping up and down. How do you not know about that? Uh, well, whatever. But there you go. Um, this is one of the originals.

doesn't even have the branding on it so one of the very first production run models haha. Fantastic! thanks rolling and Max So if you enjoyed the retro teardown, please give a big thumbs up because that helps a lot. If you want to discuss it, jump on over to the Eevblog. formal leave Youtube or blog comments and yes, I will link in the service manuals and some high res teardown photos as well over on Eevblog Comm.

Check it out, catch you next time you.