Despite the regularly proclaimed death of physical media, new audio albums are still being published on CD and vinyl. There’s something particularly interesting about Lorde’s new album Virgin however — the CD is a completely clear disc. Unfortunately there have been many reports of folks struggling to get the unique disc to actually play, and some sharp-eyed commentators have noted that the CD doesn’t claim to be Red Book compliant by the absence of the Compact CD logo.
To see what CD players see, [Adrian] of Adrian’s Digital Basement got out some tools and multiple CD players to dig into the issue. These players range from a 2003 Samsung, a 1987 NEC, and a cheap portable Coby player. But as all audio CDs are supposed to adhere to the Red Book standard, a 2025 CD should play just as happily on a 1980s CD player as vice versa.
The first step in testing was to identify the laser pickup (RF) signal test point on the PCB of each respective player. With this hooked up to a capable oscilloscope, you can begin to see the eye pattern forming. In addition to being useful with tuning the CD player, it’s also an indication of the signal quality that the rest of the CD player has to work with. Incidentally, this is also a factor when it comes to CD-R compatibility.
While the NEC player was happy with regular and CD-R discs, its laser pickup failed to get any solid signal off the clear Lorde disc. With the much newer Samsung player (see top image), the clear CD does play, but as the oscilloscope shot shows, it only barely gets a usable signal from the pickup. Likewise, the very generic Coby player also plays the audio CD, which indicates that any somewhat modern CD player with its generally much stronger laser and automatic gain control ought to be able to play it.
That said, it seems that very little of the laser’s light actually makes it back to the pickup’s sensor, which means that along with the gain the laser output gets probably cranked up to 11, and with that its remaining lifespan will be significantly shortened. Ergo it’s probably best to just burn that CD-R copy of the album and listen to that instead.
Somebody want to explain this comment:
“That said, it seems that very little of the laser’s light actually makes it back to the pickup’s sensor, which means that the gain gets probably cranked up to 11, and with that its remaining lifespan will be significantly shortened. ”
Amplification of the signal shouldn’t reduce sensor lifespan.
Might be that the gain control can modulate the Laser current as well
Power is volts time current.
Most devices follow the inverse square law where as you increase voltage, current increases proportionally.
Cranking up the power of any solid state devices generally shortens lifespan, especially as you get towards the edge of consumer grade products.
I don’t think “inverse square law” means what you think it does.
That’s not what inverse square law means, nor does it apply here. The equation for power is P = I x V, there’s no square there at all. You even said it yourself, “proportionally”, which is not the same as squared or inversely squared.
I think part of the gain circuit is the power to the laser led.
Even then, it would be weird for manufacturer to set the maximum power high enough to actually significantly shorten the laser lifespan.
Every company on Earth would absolutely let you break your own device if they can sell you the replacement.
Long as it’s not glued together. ;-)
Not true.
Not at all. It’s a common temporary fix to older lasers to boost the strength but it only buys you so much time before the laser fails
Life span of laser diodes is directly proportional to the power output. Literally everything it does will change its life span. The question is whether it will affect you over the life of the equipment.
Cars will let you drive an engine past its red line, light bulbs can be cranked up until they burn out, refrigerators can be set to max until the compressor fails, etc… Yes, manufactures will in fact let you run their products beyond its limits.
I have never, ever come across a CD-player that adjusts the laser power. It’s fixed, so I also don’t get this.
This is an LED laser, not a Star Wars lightsaber. It is not capable of transferring significant heat to the medium.
I have no idea how the signal chain works in cd player but in general, gain can also describe the emitter gain, meaning that the cd player increases the laser output until it get a readable signal or maxes out.
Except that would be an uncommon circuit design for a cd player.
(Maybe not on burners though)
I think they are talking about the laser’s gain being turned up to 11, so “it’s remaining lifespan” is that if the laser, not the sensor.
Does automatic gain control brighten the laser?
If so, the clear CD might get cooked
Absolutely nothing will be damaged.
I wonder what would happen if he spray-painted the top of the CD with silver (or even white) paint.
Granted, that’s not the same as an embedded reflective layer but… I wonder if it would improve the pickup signal at all.
When I heard about Lorde’s clear CD, my first reaction was that Weird Al needs to release a new LP on Vinyl… but one with no grooves on it because…. you know… something-something-art.
There are or were plenty of multi-disc vinyl releases where one side of one platter was an artistic, unplayable design. I have one, I think it’s Parliament Funkadelic, where the album came with a standard 45 and also a smaller single, and the single was really a single with one song on one side and the back side of the disc looks something like microcrystalline quartz or druzy quartz. I’ve seen others where there’s a single spiral that shoves the tone arm off the outside of the record.
A spiral that sends the tone arm off the record is a terrible idea. If the turntable is larger than the record, it could rip apart the stylus.
I’ve read about USB drives that destroy the USB port. Why shouldn’t vinyl have the same feature?
Because if you are a regular publisher and not a saboteur, it could ruin your reputation all the way to a boycott level and drive you out of business?
If the top is still lacquered, it could make matters worse since you’ll have a strong reflection unrelated to the track.
I second that! A square vinyl by the way.
I’d expect nothing less than him exploring the possibilities of a dodecahedron shaped vinyl LP.
Dodecagon.
You can always make the piece of vinyl any shape you want it; the tracks still have to make a proper circular spiral. Same goes when a novelty shaped CD is made.
Square “vinyls” were pretty common as inserts in follow-along books. It was still a circular track and the material was thin and floppy as if it were another page of the book
https://en.wikipedia.org/wiki/Flexi_disc
I helped develop flexible CD-ROM back in the day. Never made it out of the lab as far as know. It was these polyester sheets with the pattern pressed (cured) into UV resin on aluminized sheet and you’d cam them on to these clear CD shaped adapters and try your luck. God help you if you had a slot load drive – you were going to be taking it apart if you somehow did manage to get it to load. Tray was the only way. Reliability and repeatability were abysmal, but some players really did a much better job than others. Unsurprisingly, they were also the ones that could read the most mangled and scratched normal disks. Anyways, yeah flexible CD. They were gonna be packed with nothing but ads and malware and be everywhere from magazines to cigars , but cable modems, Napster and the iPod killed that too, thank God.
Perhaps a grooved vinyl CD with a removable center insert. A 45 rpm CD would be pretty Weird Al, wouldn’t it?
Godspeed You Black Emperor released an album called F#A-Infinite (I can’t be bothered to find the unicode for an infinity symbol) where a locked groove at the end would repeat said melodic interval forever.
Another fun fact: Monty Python’s Tie and Hankerchief, which hid a THIRD record within by placing the needle in a different set of grooves.
A different groove; there is only one track on each side of an ordinary record. There were two on one side of MP’s “three-sided record”.
I was under the influence of chemicals in a friend’s dormitory when I first heard that record. The brain takes quite some time to unscramble that experience. The next morning I had to ask my friend about the experience; wondered if it was just a screwball dream/nightmare on my part.
As someone who worked in the Optical Media industry for ever 18 years, I can safely say this is a matter of reflectivity. Betting the C2 errors are wildly out of range for some players.
So we go from three-sided (err, triple-grooved), cf https://en.wikipedia.org/wiki/Multisided_record … to none.
Spın̈al Tap would approve.
The signal is rectified and goes into the DAC. Thr big issue is whether the rectifier is triggered to give us a consistent digital signal. There must be a nominal and minimal threshold of the laser signals amplitude for the rectifier to engage and output a bit. Newer cd players may be able to read more faint cd pressings. It seems like these would be more sensitive to dirt or scratches?
The signal path is not nearly that simple. There is not a rectifier involved. CDs use a form of NRZ encoding to encode eight bits into 14 bits with reliably frequent zero to one and back transitions. Reed Solomon error correction is used on the overall data. This gives it some of the robustness that allows for cruddy CDs to be played.
Afaik Adrians style is going in blind and figuring things out on the fly thus he didnt study how reading CDs works and makes a lot of bad assumptions :(
– what wobble is and where it comes from
– what is and is not a bad/ugly signal
– what is an Eye Diagram and how to trigger one properly
no you cant :)
maybe better one is a reply to Adrian from TheRetroChannel https://www.youtube.com/watch?v=rq323smuXjo
I had to unsubscribe because of his style – I understand it works for some but it really rubs me the wrong way sometimes. Especially when he’s handing out misinformation like this.
The player that didn’t work didn’t even try. It probably has a rudimentary light-based disc presence detector. I suspect if you could “trick” the disc detector, it would probably play fine. Although the signal is weak, the SNR should still be high, and since the signal is ultimately converted to digital, it should be fine.
I believe the reflectivity of the Lorde CD is roughly the same of a CD-RW. Thus most modern tray based players should play it just fine.
Older players did indeed refuse to read CD-RWs (and very early players would even fail to read CD-Rs). But that wasn’t necessarily a limitation of the laser or the pickup, more likely it was just a threshold set too high in the firmware. I bet if you could override the mechanism that determines if a disc with enough reflectivity is inserted you could get many very old players to read CD-RWs.
Of course some of the other people experimenting with this CD are running into issues like slot load sensors not seeing a disc or, as you noted, sensors outside the main reader laser that are determining if a disc appears to be present.
I bought a copy of the CD to experiment myself and nearly every modern tray based or spindle based (like portable CD players) CD reader I’ve tried can read it fine. My suspicion is it essentially comes down to can your CD player read a CD-RW and can it load the disc without needing to “see” the disc (as in slot loaders).
Over two decades ago, I had a Thinkpad 760XD with a 6X CD drive that only worked with pressed CDs. It could detect CD-Rs, attempt to read them, but ultimately give up after a few seconds.
I have an old (old) CD player and I have noticed that it has trouble with CDs that allow a lot of light through (if held up to a lamp), where the label side is transmissive.
“Hey boss, I found a stash of leftover clear CD blanks we used to put on the top and bottom of bulk packs. What do you want done with them?”
“Don’t throw them away. I have an idea! [tap tap tap] Lorde, darling! Have I got an idea for you!”
First feeble unsteady step towards data crystals (“Star Trek New Generation” fame).
Let us not forget TOS’s Mr. Atoz, with his library of 5″ disks!
Why would anyone listen to Lordi anyway? Their music is such a cringeworthy mixture of emo, fantasy and finnish power metal it gives me cancer.
Why would you post an opinion on music when the article is about the disc? Opinions are like a**holes , evyones got one and most of them stink!
Not mine. Even though I’m straight, I still follow Van’s advice and wash those regions thoroughly. https://www.youtube.com/watch?v=L1YcEGSllYg
Not saying they should, but you answered your own question with your last four words.
Don’t worry, this is Lorde not Lordi so you can listen without the risk of getting cancer (unless you happen to be in the State of California whereby touching the CD may give you cancer). Lorde and Lordi very similar in name, very different in music but both enjoyable.
Lorde != Lordi. Their musical styles aren’t even close.
Not only is your comment off topic, but you even had the wrong band!
(just as off topic: Lordi is hilarious)
Pretty sure not a single “Audio” CD with any type of copy protection sold in the last 10-20 years had that logo.
(because none follow that standard)
Some did. But not Sony, who hid a rootkit on their CDs.
Yeah, I remember but pretty sure those CD’s didn’t follow the red book standard either.
Not because of the data partition or the rootkit but because the audio part wasn’t completely RB confirm (why should it be).
https://en.wikipedia.org/w/index.php?title=CD_and_DVD_copy_protection&useskin=vector#Changes_that_followed
non CDDA Audio CDs started around 2002, Sony’s rootkit debacle was in 2005 (didn’t check primary sources)
Does a cd player rely on reflected light? If this cd works without a reflective backing does that mean the laser is reflecting off of something in the player?
No, I would think the usable signal is still from reflecting off the pits on disk itself–it’s just a much weaker return. Laser light that passes through the disc and reflects off parts of the machine would be out of focus and would just be picked up as ambient noise.
There is still a reflective backing, it’s just a lot less dense than a standard CD. Also note that the laser is infra-red, so it only has to be reflective to IR, it can transmit all the visible light it wants.
who thought this was a good idea? do people just buy cd’s as a keepsake and not even play them?
Probably yes, just like current releases on vinyl. Lots of people buy the artifact and listen to the album on streaming or digital download. There was a study a few years ago that found that half of people who buy vinyl don’t have a record player. I wouldn’t be surprised if lots of people these days don’t have a CD player either. I do, but I never use it.
Look at Taylor Swift’s vinyl offerings; one album in four different colors of vinyl (each being almost 3x the cost of the CD!). There are undoubtedly people who collect CDs/DVDs in much the same way, without using them. I’m surprised that she hasn’t brought out multiple colors of her CDs, the Swifties would eat ’em up.
I should have looked more carefully. Swift already has multiple “collector’s edition” of some of her CDs. So it’s a definite yes, some will buy CDs and never play them.
Evidently she’s never seen a CD in the flesh either.
Since most CD players use an infrared laser, would it not have been possible to use a dichroic reflector to prevent the problem (i.e. reflective to infrared fut transparent to visible)
It’s actually an incomplete CD is all it really is. Missing the reflective layer to look cool, not understanding how the medium works at a basics functional level
Try looking thru glass window with a Thermal camera to get an idea.