Technics SL-PG100 hardware hacks: Adding digital audio output and remote control

🛍️ Tindie store: www.tindie.com/stores/theretr...
🛠 Tools and kit: / tools-and-kit-77570017
💬 Discord: / discord
😎 Ad-free, early access: / theretrochannel
🔗
Optical connector TOTX174: www.aliexpress.com/item/10050...
Service maunals and specs:
SL-PG100: www.hifiengine.com/manual_lib...
SL-PG200: www.hifiengine.com/manual_lib...
SL-PG300: www.hifiengine.com/manual_lib...
SL-PG400: www.hifiengine.com/manual_lib...
SL-PG520: www.hifiengine.com/manual_lib...
🔗
🎞
0:00 Intro
2:55 Adding components for optical out
6:19 Testing the optical out
7:08 Rear panel holes
8:41 Remote receiver?
11:22 Remote connections
13:36 Remote testing
14:56 Finishing up
17:33 Digital vs analog comparison and notes
🎞
Thanks for watching!

[@gertsy2000]

Feature envy resolved! Kind of amazing that these tiny component differences resulted in a different model worth $100s more.

[@BICIeCOMPUTERconGabriele]

Well the digital output jack costs 12$

[@JoeBlogs720]

Ahhh I remember waking up Christmas morning when I was a kid opening my presents and take them immediately apart, they never did work again but maybe I learnt something.

[@Tater-Chuck]

I remember tearing apart everything that sat for more than a week, including a BEAUTIFUL CBM 8050 disk drive that's now worth a couple grand. 😔

[@antiphlex]

Same here, guilty as charged. I even went dumpster diving, much to my mother's chagrin, for old electronics just so I could tear them apart. Fun times.

[@ABC-rh7zc]

@@antiphlex LOL, I thought that was just me. I went to the local flea market to buy broken old electronics to mess with. Managed to electrocute myself a few times too.

[@apersonwhoknows]

I would've been clobbered for doing that.

[@TheBasementChannel]

Love these series of cd players. So responsive and reliable. Look good too. I wonder if anyone did this mod back in the day, a few cents to upgrade to a model worth hundreds more would be an attractive proposition.

[@jandjrandr]

My brothers and I used to open our electronic toys, etc once we got tired of playing with them and sometimes when they were reassembled they still worked. Fun times. We got better over the years so I think we learned a few things. As far as telling the difference between analog and digital recording, I definitely could. There is more analog high frequency noise (hiss) in the background of the analog recording. Not much, but enough to hear it. I called out which one was analog and digital before I looked at the screen to see which was which and I was right. The longer the signal stays digital will almost always reduce the noise in the sound.

[@BlackJedi169]

Your first sentence had me laughing.... When I was young and did the same things as you.... Cross my fingers and hoped it worked when I put it back together... Why have I got 4 screws left over.... shit Late 80s and 90s now we can use our phone and take nuff pictures of the board and we're all the screws go😊

[@BTW...]

LOL. Same here, starting in the early 60's, before I can really recall, so family and friends say. 'Spare Screws' yeah... I always seemed to have the most problems working on Toyota cars. As an apprentice, the lurk was to 'donate' an extra screw or two to the tradesmans disassembled job on hand. It would send some of em mad as a meat axe.

[@minus3dbintheteens60]

The optical unsurprisingly has a higher dynamic range. Cool mod, I'm only an armature but I've long been interested in modding digital out into car headunits. I guess jumping directly from the DAC output to a coax RCA output, but I'm yet to try so far. It's not a project as easy as this where a feature that was engineered into the product has been disabled by removing a couple of fully listed and detailed components

[@profpep]

We used to call these tricks 'Sidegrades'. My best ever was adding the rear channels to a friend's Volvo car audio system: a couple of chips a handful of passives, and something like £30 for the actual speaker kit and he had a £300 upgrade.

[@merlin5476]

I have the pg 420A version for around 40 yrs and its Never missed a beat. Awesome machine.

[@timschulz9563]

We have that thing too at home. 5 years ago it had trouble scanning the tracks but after removing the dust from the lens, it works like a charm again.

[@SubTroppo]

My CD player remote hack was to find a Sony DVD player in a kerb-side clean-up and a remote for another Sony non-working DVD player two years later in another kerb-side collection. [no finger heating required but the Qld sun was quite fierce]

[@tinkering_geek]

What a great result. I feel so dumb thou. I've seen these unpopulated foot prints so often and always wondered how difficult it would be to see what these missing features were. I never considered looking at a service manual for the next model up to see what goes there. Its so simple yet I've missed that for 20+ years. I had a Blaupunkt VCR that had all sorts of features, it was a great machine, but there were more IO options not populated and I kept going back to it time and a again in an attempt to hack it somehow. Although this was around 1990 so the internet wasn't an option and the old viatel 75/300 BBS service was pretty poor. But if I find that old beast I'm definitely going to mod it now. Great Vid.

[@Cyba_IT]

Yeah, without the internet it would've been near impossible to get service manuals back in the day. I suppose you'd have to write to the manufacturer and request one.

[@michaelturner4457]

I've heard that KZbin Audio Library piano music a few times now, when it's used to audition the the wow & flutter in those new cassette walkmens that have been reviewed by various KZbinrs.

[@TheRetroChannel]

Haha, yeah I'm pretty sure I've also used it in one of my other videos to do just that

[@jjolleta]

That was the first cd player I bought for my home teather back when I was 15 yrs old !!!! Nice memories.

[@paulb4uk]

Superb job amazing how simply and cheaply the mods were

[@TomJordans]

Great job - terrific video. I have several older CD players. Fun to watch you hack this.

[@Seiskid]

I have this player upstairs. Wondered in the past if adding a remote was feasible. Super easy. Thanks for the vid.

[@andrew1977au]

Love your videos mate! Make me laugh at times.

[@esseferio]

Great video, really enjoyed it. You should do more vintage audio, really :)

[@tonep3168]

Great video!

[@ColdRFusion]

Great work, those jumpers are tricksy but no match for a multimeter!

[@PileOfEmptyTapes]

This is the kind of hack I like. A few remarks: 1. An IR receiver window does not necessarily need to be transparent to visible light, in fact I imagine keeping that out might even help reliable operation when you've got a strong visible light source shining on it. 2. Jazz trio has been found to be among the least revealing styles of music for listening tests (despite its popularity in these). This recording also seems quite bass-deficient. 3. The UCA222's ADC isn't all that great, even if it does still have the original PCM2900 rather than the Coolaudio version found in newer specimens. It's about on the level of the PG100 itself at best (and obviously you don't want your ADC to be the bottleneck). The thing also cannot take the full 2 Vrms maximum CD player level, it's specified to +2 dBV which is about 1.25 Vrms. According to the chip datasheet, maximum input voltage is 0.6 times Vdddi (which is 3.3 V) or 1.98 Vpp or 1.4 Vrms. It's the kind of thing that was intended for digitizing your cassettes and records and things like that.

[@Projacked1]

That is cool , I have to check my TEAC cd-player (CD-P1260). It doesn't have digital out either, but an excellent player.

[@S.T.G.]

Thank you so much for this video. The headphones output could also be interesting...

[@TheRetroChannel]

Yeah, looking at the service manual for the higher models they have an extra PCB for the headphone jack and volume control. It also has a small amplifier circuit to power them. So it's possible, but not worth it imho

[@kapilsds7]

I had done remote sensor adding thing to CRT tv sets my school days.

[@mk500]

Great clean upgrades! I thought your metalwork was quite good. I admit to being a DAC snob, so this would be an upgrade I would do also if I had that player. I was surprised it was that simple to add the remote.

[@TheRetroChannel]

I almost didn't expect the remote to work so that was a nice surprise. I have a budget DAC which does sound better than the inbuilt one in my receiver, one day I'll invest in a good one

[@RacerX-]

Super cool.

[@kitvar2685]

Brilliant! I have this exact CD player and always wondered given the board has traces and holes for a SPDIF output if it could be done successfully.

[@MrFixiit]

nice job :D

[@BryanTorok]

My initial impression is that the bottom track sounds a tiny amount brighter or crisper on the high notes, perhaps almost tinny. But then I listened with my eyes closed and the difference is so small that I can't tell which track is playing. Now, I have 60-some year old ears with high frequency hearing loss and I'm listening on cheap computer speakers. Some day I'll get this hooked up to decent amp and speakers.

[@BigSneakySnake]

My dad had the same CD player, noice!

[@scaleartsg]

im here for the jazz!

[@gieselats]

Thank you for sharing your experiences. I always love it when things get repaired or improved. Really awesome. I have an old sony cd player. But the player doesn’t work. No disk failure. I fear the laser is the broken part. But i have hope to repair it. Maybe i will find an Exchange laser on ali express. But i am not sure if this is a good idea. Keep up good work. 😊

[@TheRetroChannel]

Yeah AliExpress is like a lucky dip for these kind of things. I'd hunt down the service manual if possible and see if you can confirm it's a dead laser

[@gieselats]

@@TheRetroChannel thank you. Service manual. I go for it.

[@canangagasan]

Great video! This one and part1 not only triggered me because my first CD-player was the 200 model (with headphone out), but because of audio-tech in general. So this video nicely fits between retro computing, audio-streaming with raspberries and the likes and diy-speaker building. Would love to see some more of it. Is there a way to pick up digital audio from the SID of a C64?

[@TheRetroChannel]

No chance for the SID, totally different beast

[@gregdunlap7538]

I can't tell the difference between the analog and digital audio, they both sound great to me! But I'm listening through Bluetooth earbuds over KZbin, I'm probably not the best judge! LOL

[@oggyosbourne]

Nice video! What model is that Samsung Galaxy Tab?

[@messageobliquespe100]

Enjoyed the vid/mods - nice idea to mod similar equipment so might look at what I’ve around to do in the future. I’ve found that CD players are pretty cheap these days on eBay I’ve sold a few that I had stored away & it was difficult to get much for them tbh. I was surprised at the interest of the oldest one which sold for £150 - SL-P770 - No idea why it commands such a price - but seen one advertised at £480. Maybe there’s a list of CD players to look out for? My equipment requirements don’t require high end anyway as I wouldn’t be able to tell the difference with my ears! I think I’ve two Technics CD players in the garage - newer than the 770 sold - but they don’t look as good

[@scottb721]

Awesome vid. Check the Harmony for discrete ON and OFF commands rather than Power Toggle.

[@DaXande135]

This can't work if the power switch is mechanical

[@scottb721]

@@DaXande135 some mech switched devices still have a soft off/standby capability.

[@DaXande135]

@@scottb721 But most don't have such a feature, at least that's my experience with mid range hifi equipment. Maybe some older higher end equipment sometimes may have such a feature, but I think in the era of this Technics CD player, they would already have implemented it with relais if it was remote controllable. For example my mid 1990's Techncis amp uses relais for standby/on, instead of a hard-power-switch.

[@coondogtheman]

Curious if there's a mod that can capture the raw audio data coming off the CD and encode it straight to a wav file as the disc plays.

[@Johny666EU]

if you connectors doesn't want solder then clean then in IPA, many times there are in greased or in oil. they prevent soldering. its related to every item you want to solder. ps get solder wick, youll see how easy is to remove solder from board and clean the pads. anyway nice job. ps, dont terrorize the button so much, they need easy pressing insted of using finger hummer.

[@e.emerald3224]

Think I had a 450. The next up was a 550??? A mag review said the only difference was film output caps and indeed sounds better

[@Gucenmis]

Man, is it possible to install a more useful alternative remote conrol for the Akai SS-4100 sound system? Thank.

[@glynnetolar4423]

So, anyone remember the Technics CD player that had the linear motor for the drive? Don't remember what they branded it and I wondered if this unit had that feature. It was good to get from one end of the CD to the other FAST.

[@CinemaDemocratica]

What about a digital audio input? The best-sounding DAC that I have ever heard is inside an integrated CD player -- the Arcam FMJ CD23. I have the technical manual. If I could find an example of the player, would you and your team be willing to give it a go?

[@voltare2amstereo]

love a mod can see in the waveforms, the analogue is flat topped (the peaks are the same level) the optical capture is nore variable - could be a limitation in the recording you took

[@TheRetroChannel]

Yeah, I don't know why. I've used the Behringer UCA222 for a lot of captures and never had this issue before so I suspect it's the DAC in the cd player

[@AnnaVannieuwenhuyse]

@@TheRetroChannel It doesn't look like it is; it's too precisely at one level. If it was in the CD player, you'd expect the analog filtering happening on the input of the UCA222 to cause a change in the peaks. It looks like digital clipping, i.e. level going too high for some part in the chain. You can confirm this by checking the samples at the clipped sections, and seeing if they flatline. It was audible to me that some of the drum hits were noticeably clipped, and this initiated me to check out the comment section! :) Additionally, the UCA222 is really not that great of a device in general, unfortunately. It has some limitations you can't just work around.

[@TheRetroChannel]

Good point. I did have a look, but didn't include it in the video. The peaks are flat, so definitely clipping happening somewhere. I'm going to do the same tests with another computer to see if I can narrow it down.

[@AnnaVannieuwenhuyse]

@@TheRetroChannel them being flat largely eliminates an analog issue. I can check whether I can find a Uca222 to run some tests on to see how hot it allows inputs to be.

[@JamieStuff]

There may be another jumper on/near the power supply board for power toggle.

[@TheRetroChannel]

True, I'll have a proper look soon

[@Cyba_IT]

Nice work mate! Could you tell me what the model number of that Logitech remote is please and is it ok on batteries? I have an older one with monochrome screen and it's cool but chews through batts. Maybe that's normal and I'm just used to modern remotes lasting months or years.

[@TheRetroChannel]

It's a harmony 650. The batteries last about 6 months with rechargeable eneloops

[@Cyba_IT]

@@TheRetroChannel Awesome, thanks mate, much appreciated.

[@selli69]

If you really happy with the quality of th D/A stage in this CD player, I recoomend a visit to the next ENT physician. He can probably help you. Good Luck!

[@TheMcflyster]

Nice hack! I have the PG-300. But its skipping tracks so I have tried to clean the lens. Clean the spindle motor. Finaly I tried to trim the laser but it dident work... It seems hard to find new lasers for these machines and thats a shame becouse its a classy machine!

[@TheRetroChannel]

There's some adjustment procedures in the service manual for the laser, but you need a good digital scope or an analog scope to capture the RF eye pattern. I checked mine and it was already spot on, adjusting it just made it worse.

[@messageobliquespe100]

They’re plenty of CD players on eBay for parts - or working condition for not a lot of money. That’d be my go to

[@djcalle1975]

nice work. What you can do is buying a super cheap L336 learning remote and program it from your harmony.

[@TheRetroChannel]

True, but I have about 5 remotes that I'd like to replace with one

[@BTW...]

@@TheRetroChannel Maybe they mean you can get a remote for it to sell off the player. Difficult to sell with or without a remote I guess. It there a master library of these remote key codes, so you could re-program any old basic RC to suit any Audio/Visual gear?

[@johnshaw359]

You can use a smartphone camera to detect IR remotes.

[@SirHackaL0t.]

Dave Brubeck? It’s been a while since I’ve listened to this. The digital output ‘should’ be better as it’s not been converted to analog then converted to digital via the behringer device.

[@GalderGunn]

The plastic in front of the IR receiver is probably transparent to IR.

[@rimmersbryggeri]

YOutube compression might be the smalles of our problems . For me at least the limiting factor is probably the laptop speakers even if they are relatively decent on this one.

[@AiMR]

Would it be feasible to upgrade the DAC?

[@TheRetroChannel]

Probably not, and using a the optical out with an external DAC gives you way more options

[@AiMR]

​@@TheRetroChannel Yeah, you are absolutely correct. Just do the D/A conversion outside of the unit. I was just curious if it was technically possible because I wonder how the technology has evolved over the past 40 years 👍

[@seanwieland9763]

3:19 My autism/OCD at the wrong resistor value being used, even though it doesn’t really matter. 😅

[@TheRetroChannel]

I was waiting for someone to notice

[@hakkertje100]

Lol i have the exact same one in the living room

[@ItsJustJer]

Digital sounded more crisp actually.

[@owenjbrady]

not using flux is like taking a piss without holding on

[@shangrilai1990]

Twitch notifications come through late all the time, now my KZbin ones are too!? Here's your cookie 🍪 I'm going to mutter things about technology in a corner like an old man.

[@TheRetroChannel]

💻🔨

[@DJZofPCB]

you got lucky that the operating system was the same version in the lower end model, and it seems that they used the same operating system in all their models and just added components for the higher end models.

[@darrenmurphy6251]

Standard issue new old stock pin invisible crustyness a pencil rubber and deoxit is the cure, or wire wool if you don't mind the mess that makes

[@darrenmurphy6251]

As far as I understand the ir receiver modules have a selection of different carrier frequencies and have built in filters to reject the wrong ones so to randomly select a working ir eye like that is very good luck

[@fu1r4]

A CD player without a remote? 🤔

[@MarioMania05]

It sounds the same to me, Maybe it's KZbin

[@johnmax5652]

digital sound = more metallic / analog sound = more mellow/wooden ...

[@Gunstarrhero1]

build your own remote, you could get gum keys or something like that, switches. why not try an Arduino or a pi pico or something. you have the ir transmitters, couldnt you just use an led or something? should be too hard for you to copy someone else's remote, 3d print a case. paint it. you could just get a small led screen, like that logitech remote, copy their software over to your own model. would make a cool video.

[@TheRetroChannel]

It may make for a cool video, but that's a lot of work just to achieve the same goal

[@j7ndominica051]

12 dollars for an output jack? If they paid this price for every element, the CD player would costs thousands.

[@blackhawk606]

Just by looking at the graphs, something ain't right with the analog recording. Peaks are obviously clipped. Check your analog to digital recording path maybe you have soft clipping enabled or something or windows is working its "magic". Try using 3rd party ASIO drivers when recording from analog if your sound card doesn't support ASIO natively, this will lock windows from intruding into the process.

[@TheRetroChannel]

Yeah, it's worked fine in the past but that was with a different computer so it's possible windows is screwing with something

[@Synthematix]

Adding a digital output to one of these allows playback of DTS 5.1 audio CD's

[@TheRetroChannel]

I'm familiar with DVD-A and SACD, but I never knew DTS 5.1 CDs were a thing, had to look it up. Sounds like the format was pretty much doa

[@Synthematix]

@@TheRetroChannel Hmm not really it was a home recording format more than anything, grab a copy of the SURCODE DTS 5.1 encoder you make a 5.1 soundtrack with 6 mono wav files using it.

[@RebeccaTurner-ny1xx]

Given that the cost of the additional components is so small while the retail prices of the CD players were much larger, what should this video tell us about pricing of home entertainment products under capitalism? Here in the UK, I'm not sure if any major manufacturer ever released a hi-fi CD player _without_ infra-red remote control, so far as I can remember. Even really cheap ones in the 80s had little remotes.

[@jwhite4]

Maybe just marketing. It could have been they could advertise, "Technics CD players from $$." That gets people looking at them. But then they see for $ more, you can get remote control, $more for digital audio out, $ more for headphone. All of a sudden, you have some people that are paying $$$, that maybe never would have if that was the original advertised prior.

[@ford1546]

Hello. This is the wrong model of this look and model year. A slightly higher model and you would have had Philips' famous swing arm laser and not a super cheap one like this one has. Not worth doing this on this model 

[@TheRetroChannel]

The 200, 400 and 500 models used the Philips mech, the 100 and 300 used this one. Either way it plays everything I've thrown at it including some very scratched discs that other players struggle with so 🤷‍♂️