Stero channels aren't encoded in the depth and radial axes. They're encoded in the same plane, but rotated 45 degrees, so a mono record player (depth only) plays a balanced sum of each channel.
Maybe you are looking at the wrong one ? It loads instantly. I do not have to zoom to read the text. No node.js, cdn and other curses of "modern" web. The only annoying thing is that the guy went to great lenghts to get the audio only to convert it later to mp3. I guess there is no hope. ( it could have been worse - webm).
When I read the title I immediately thought of a "laser tip" that and reading the reflections of it, not something based on software that would "read" an an image.
Following this animation I'm left thinking that you could do a bit of filtering to better extract the wave(s) from an image, though you'd require a particular setup for the lighting conditions to get the best possible quality out of it. And then back to my first idea: probably a laser-tip would be the best tool here too.
Unfortunately I don't have vinyl records around to test any of this!
Old Edison disc records encoded single-channel audio in the vertical axis (varying the depth), but regular 78s and single-channel vinyl records encode the audio in the horizontal axis.
Carl Haber, a guy I worked with at LBNL[1] about twenty years ago pioneered this technique, at least as far as I know. The really cool thing about it is how it can be used to play very fragile recordings without damaging them.
"The method has been used to successfully play several recordings for the first time, including an 1860 phonautogram, the oldest known sound recording of a human voice, and the only known recording of Alexander Graham Bell’s voice."
These are so wonderfully distorted. I am getting somewhere between the signal in the movie "Contact" and whispers of the hive mind of the Borg. Amazing sounds, even if they aren't true to the recording.
Aside from the slight wah wah effect they are pretty great. I immediately loaded them up in my S2400 and resampled them to 12bit 26khz to add much aliasing Sample C2 is especially haunting this way.
I actually got to hear one once. Extremely neutral and high-res, but the record has to be super clean because with the laser, you will hear every little speck of dust. Also it doesn't work with colored vinyl, iirc.
edit: they use 5 different lasers to get the data out of the groove, go read the section on their site, it's actually really intricate and cool
> the format has some funky EQ and other things to make a physical needle work better
Yes, in order to fit the high bandwidth music signal into a groove with a fixed width, the bass is EQed down and treble EQed up, since for a constant velocity sine wave, a low frequency wave would take up more physical width on the record than a high frequency wave. Without this EQ, you would only be able to store a small amount of music on a record. When the record is played, your phono preamp applies an inverted EQ curve to restore the signal to its original frequency response.
In the past, there were lots of different vinyl equalization curves, but the RIAA curve has been standard for decades now.
Cleaning with glue isn’t that difficult, buy the arts and crafts acrylic white glue mix it with water and spray it on the record (30% water / 70% glue works for me).
Silly putty can also work in a pinch but some of them leave an oily residue.
Spin clean works but the cheap machines can easily break the record and the expensive ones are expensive as fuck and can still result in damage due to user error.
The problem is dirt, which sounds like a minor issue, but it renders the concept almost completely useless.
A stylus pushes dirt out of the groove as the record turns. A laser cannot do so, and it's virtually impossible to fully clean a record.
The only remaining advantage is that a laser turntable does not wear out the disc, and it's an incredibly minor advantage, compared to simply playing a record once on a traditional player, and recording the output.
Like I said, I literally heard it. The guy cleaned the record just before playing it and it sounded amazing. Doing that each time would be a huge hassle so I'm not sure if I would ever want to own one.
Slide/negative scanners use multiple passes and depth perception to cleanly ignore dust on film. I'm surprised that this wasn't part of ELP's spec to the engineers. A giant fail if they can't even remove this noise in post-processing.
There's no AD step in the ELP. it's an analog system from the laser to the line out. So there's no way to do multiple passes while listening to the record, though you can adjust the depth in the groove that the laser scans.
I wonder if they could do what film scanners do - they use an IR channel.
EDIT: and as soon as I submitted I realize film scanners scan for light and maybe use the IR channel for physical scanning. with a record everything is physical.
or maybe the IR channel focuses on a different plane? could they use different wavelengths for distance sensing/separation?
Yes that's also very important - the inverted EQ applied by the phono preamp pushes the noise floor way down in the treble, while raising it in the bass. In my opinion, this is probably why vinyl can never compete with digital when it comes to clean-sounding bass, but can generally have equally detailed treble when cared for well and played on a good turntable
Dolby NR was intended to be that way as well, but turning Dolby (type C) NR on removes tape-hiss from non-dolby tapes while also as GP said fading certain frequencies.
The funky EQ is the RIAA curve[1] - by essentially rolling off the bass and boosting the treble you can fit more on a disc, it attenuates some of the clicks and pops and is kinder on the vinyl and needle.
It's trivial to invert in software, and as another response points out, there is indeed a working laser record player - although the record needs to be extensively cleaned before playback or it doesn't work very well.
That doesn't make any sense. RIAA EQ is a serialization format, that is then decoded by your audio equipment. That's what the phono jack is for on a receiver, pre-amp, etc.
What people "hear" regarding LPs is generally their biases + their particular analog setup. My setup is going to sound totally different than yours, regardless if it's from a CD or an LP.
There are some cases where an LP had a better -master- than a CD for the same release, but that is due to the publisher/owner of the master tracks and not the actual medium itself.
I found out when digitizing vinyl that LP's before 1977, when digital mixing and mastering was not the norm that there is more data in the frequencies between 20 and 50kHz. I do my recording standard at 192kHz and analogue LP's often reach 48kHz of data while digital mastered ones do only 22kHz. After that date often the frequency is cutoff at 20-22kHz, probably to save memory room. Only after 2000-2010 there is enough memory to record at insane sample rates and bits per sample. Most awful are cds having only 16 bits and 41kHz sample rate, by modern standards really poor.
"Most awful are cds having only 16 bits and 41kHz sample rate, by modern standards really poor."
44.1kHz is all that one needs for -perfect fidelity-, given that humans cannot hear higher than ~20kHz. See: Nyquist-Shannon Sampling Theorem. [0] 16 bits of quantization gives a Signal to Noise Ratio (SNR) of 96dB, and noise dithering increases that [1]. More bits are not necessary unless one is doing music production with that audio and warrants the extra headroom, before mixing back to 44.1kHz/16bit for distribution. [1]
The only thing that higher bits/sampling rates do for a listener is waste CD and drive space, so it is odd to lament 44.1kHz/16bit as being "really poor". Even if your speaker setup can actually output extremely high frequencies, only your dog will be able to hear it...
I am doing production with these recordings, tools are more precise at higher bit and sample rates. Also quality of listening equipment is a factor as hearing is not a flat frequency response, things as ambiance and resonance play a role, music is not a single frequency tone but a combination of complicated frequency additions, subtractions, multiplications and divisions. So more frequency room can produce nicer highs and clearer sound, especially when music is uncompressed.
It is simplistic to state that 44.1/16bit is enough, if that is the case then any combination of recording, amplifier and speaker would suffice.
This just isn't the case, also that we would need awesome priced equipment isn't really worth it.
But there really is a difference between a phone with a music app playing a 16bit/44.1kHz song on a medium quality headphones and a dedicated player with a good DAC chip playing a 96kHz song on a good quality headphones.
People that cannot hear the difference should not invest in such equipment and will be happy with the need to invest less money for their entertainment.
44.1/16 is enough for distribution. This is not simplistic. It simply can reproduce waveforms up to the nyquist frequency perfectly within a defined noise range. That's a mathematically proven fact. Of course you can botch that with bad listening equipment, but there's nothing a ridiculously oversampled signal would improve given the same listening equipment. You do speak about the studio processing right?
>It is simplistic to state that 44.1/16bit is enough, if that is the case then any combination of recording, amplifier and speaker would suffice.
No, that doesn't follow. It just means that recording at those bit rates and sampling frequencies isn't the "bottleneck" for the sound in the system.
>But there really is a difference between a phone with a music app playing a 16bit/44.1kHz song on a medium quality headphones and a dedicated player with a good DAC chip playing a 96kHz song on a good quality headphones.
When everything you compare to is better quality then of course it sounds better. But it's not due to the 96kHz vs 44.1kHz. Nyquist-Shannon is mathematical reality.
You have to compare the same high quality headphones, the amp with the same DAC, with the same recording, being played through a high quality filter bringing everything down to 44.1kHz/16bit.
"You have to compare the same high quality headphones, the amp with the same DAC, with the same recording, being played through a high quality filter bringing everything down to 44.1kHz/16bit."
I agree. If there is a methodologically sound study showing that people can actually distinguish (>50%) between 44.1kHz/16bit and 192kHz/24bit on the same hardware [at exactly the same dB SPL], then I will be really surprised. It's not physically possible to hear those differences, as far as I understand it.
Some humans can hear much higher than 20khz. Very little of our recording and playback equipment does well above that point, however, so efforts to reproduce that part of the spectrum most often fail miserably.
But that is for a pure tone under perfect laboratory conditions. Also, they report that the minimum hearing threshold at those frequencies was above 90 dB. So I don't think any human in this planet can actually hear anything above 20 kHz under normal circumstances, much less for music.
Yes, but that'll be captured in the CD range with the rest of that signal. My feeling is that few instruments, no music and little transducer equipment exists for that range (>20khz), and so few are aware of it without the intermediation of technical assistance, that theres no point in attempting to record or reproduce any of that. all it can do is add noise.
They've got some lovely high bitrate and bandwidth recordings there, and what they've caught is room and audience noise. They'd have benefited from more mics and mixing and less "throw bits at it"
Most likely, CDs just don't get mastered right. The music is compressed and so even though the format is better, the music is worse. Vinyl is sold to people who care about sound, in their living rooms so they get better mastering. Digital is for people out and about, in your car you need compression even though it destroyes the music you can't even hear 3/4ths of the sound without it. This isn't the fault of the format, but the result remains, digital music is objectively worse.
Vinyl is able to get a slightly better S/N ratio in perfect conditions. So if the record is new it might be better (every time you play the record you wear it just a bit). Odds are it isn't, as almost nothing has enough dynamic range for this to matter.
They are used to worse sound and prefer it. CDs are perfect - vinyl often introduces imperfections that people like to hear. By objective measurements the music isn't perfect, but they like that imperfection.
Most likely it is the first. It is by far the most significant difference.
"Vinyl is able to get a slightly better S/N ratio in perfect conditions."
No. Compact Discs have an SNR of 96dB. Vinyl typically has an SNR of 60-70dB. The physics of these mediums aside, CDs are a newer technology... Why would we have gone for inferior distribution mediums?
"Most likely, CDs just don't get mastered right. The music is compressed and so even though the format is better, the music is worse"
Compression like that has more to do with radio play + the genre of music. Thankfully, the loudness wars are mostly over, but generally speaking the actual distributed master would've been the same.
"This isn't the fault of the format, but the result remains, digital music is objectively worse."
Please provide such objective citations. Mixing and mastering engineers do their best to make music that sounds good on a variety of audio systems. When I worked in a studio, we would mix on $8k genelec monitors, some cheaper monitors, and also test the mix in our cars and on our phones. Part of the art and difficulties in that was producing a mix that sounded good on great to average systems, and passable/decent on like mono phone speakers. Music and music hardware has never been more accessible than today, so I find it hard to believe that everyone a few decades ago had such amazing systems compared to today.
"Vinyl is sold to people who care about sound"
Citation needed. There are people who just want vinyl because it looks cool (especially the colored limited releases), and they go play it on a $50 Victrola all-in-one. There are CD enthusiasts who have systems worth > $200k.
"CDs are perfect - vinyl often introduces imperfections that people like to hear."
This is totally subjective. A CD is a bit-for-bit perfect representation of what the author wanted to distribute. The actual things like "warmth" that people talk about depend much more on the pre-amplifier, amplifier, and speakers.
There is nothing wrong with liking LPs (I collect them myself), but they are in no way, shape, or form better than the bit-for-bit perfect distribution of CDs (that also don't degrade every time you play one).
And even with that, "the best technology wins" isn't always the case. One could make a reasonable argument laser disks were better than video tapes and that Beta was better than VHS.
There are forces beyond the pure technology comparison at work in market dominance.
>"When I worked in a studio, we would mix on $8k genelec monitors, some cheaper monitors, and also test the mix in our cars and on our phones."
Yes! When i was producing an album a year, i'd write in monitor headphones, master on bookshelf monitors + a smallish subwoofer, then computer speakers, my car stereo, and a friend's street comp A car stereo. It's the only way to be sure that my ears in the "studio" weren't being biased by the overall quality of the sound damping and accoustics of the room.
And objectively, i know that CDs are "pure". I also really can't hear the difference between a mastered 96khz 24 bit raw audio file, FLAC, or ~300ABR Mp3. And before it's mentioned, i have much better hearing than anyone i know, even if i have lost the ability to distinguish words when someone talks to me off-axis. the other night i heard my nearest neighbor playing music, and no one else could, here. Neighbor is like 1/4 mile away, from inside their house to inside my house. I brought my tascam to the back door and recorded[0]. Sure enough, the recording has a high noise floor but you can see the bass hits.
I still prefer live electronica shows where the DJ has pennies taped to their stylus, but i watch DJs on twitch using laptops and DJ-I digital turntables. All this to say, i've never made fun of someone spending thousands on pre-amps, amps, speakers, decks, whatever. If someone likes the way a Marantz sounds, or a Pioneer, or JBL or klipsch speakers - it doesn't affect me at all.
We're not using skippy CD players and realaudio/56kbit mp3s anymore!
> I also really can't hear the difference between a mastered 96khz 24 bit raw audio file, FLAC, or ~300ABR Mp3
An MP3 file at around 300kbps should be pretty much indistinguishable from FLAC for a human, so that's not surprising at all :)
The reason why I keep my music library as FLAC is not because it sounds better - it's because it's a perfect lossless copy of the original source that can be encoded to something lossy should a need arise. If I had to make 128kbps Opus files for some mobile use case, I'd rather do that from FLACs than MP3s. It also avoids double lossy compression when using things like A2DP.
> Compact Discs have an SNR of 96dB. Vinyl typically has an SNR of 60-70dB.
you are confusing typical with what it is capable of in lab like conditions. I agree in real use CDs have a better SNR.
> Thankfully, the loudness wars are mostly over, but generally speaking the actual distributed master would've been the same.
The loudness wars being over helps a lot. However vinyl often is mastered different. Just because you didn't do that doesn't mean others are not. For the few who bother with vinyl of course.
> they are in no way, shape, or form better than the bit-for-bit perfect distribution of CDs
I didn't mean to imply that. I only stated that in ideal conditions they can be better, and that often they get a better music going in. The first of course assumes always fails when put into the real world. The second is very much YMMV, but happens just often enough to be aware of.
Thinking about a simpler system... how about getting a camera on a turntable recording a video while the record turns. It would then be possible to track a line with an specified width in the video and turn the changes in a piece of this line it into a waveform.
Also capture the audio sample from the same record alongside the video. Repeat with lots of records. Train a model to predict the audio from the video. Voila! Play records with just the camera “stylus”...
Random Q: do I have a damaged/bent stylus if a certain record (Toots and the Maytals' Pressure Drop picture disc) goes silent at several different times? I checked the stylus force scale at the different test points, and it's right in the middle of the cartridge specs.
Every other record plays fine, except some new records play slow and/or some carve out a thin hair of lacquer/enamel the first time. This always makes me think some sort of damage is happening from a misaligned cartridge. But, other good quality and used records don't do this and work fine.
If it is just happening with a specific record (especially a picture disc) it's likely not your stylus and just the pressing. You can give cleaning your record and stylus a shot and see if that helps.
If records are playing slow make sure if your table is belt driven your belts are still in good condition. Also make sure your tonearm height and anti-skate are properly adjusted.
Cleaning your records before you play them (even brand new records) is important.
It's a direct-drive Panasonic PL-5 with the internal calibration strobe, so no belt.
I always clean them with a Zerostat and Discwasher. And have a Japanese stylus cleaner too (the stuff that looks like a breast implant for mice porn stars.)
The local record store has the same record, maybe they'd compare them?
Now I'm dreaming about a program that would simply play a high-res photograph (scan) of a vinyl disk...
This also reminds me of the idea to use paper for archival. This is based on two factors: that modern office paper is extremely durable (and is likely to outlast most of the other physical media out there), and that scanners are (and have been for years now) extremely high-resolution; so, you can simply print the bits (say, of a zip file) as dots, and then you could use a scanner to read the file back!
Interesting concept the biggest problem would probably be data density. Like how many papers would you need to to get about dvd size. Other than than the problems in getting a reader dvds is one of the best current long time solution.
Wayback Machine does indeed has archives of the page from 2013 onwards, but while googling "Vinyl-ROM" (inspired by comments in this thread) I found a reference to this exact huji.ac.il page in a comment thread on Halfbakery dating back to 2003:
In fact the parent URL does have WayBack archives going back to the early 2000s, which include this content. dang: I nominate the date for this item should be listed as 2003.
I remember seeing something online a very log time ago where someone was using Perl to encode audio into image files (jpeg IIRC) and then subsequently decoding them (losing fidelity in the process). Even though I understand the science that makes this work, it still feels like magic. Love it.
You're joking, but based on the dynamic range (claimed by audiophiles) over a min length of ~160um (more on the outside less interior for 2kHz tone) and the peak motion ~37um per channel.
PVC grains are typically 100s of um in size, but the monomers themselves are ~10nm. Note that with 120dB claimed dynamic range this would be 37nm of deflection (at 45deg or 25nm lateral) for full resolution. That is close (3x off) to molecular Atomic Force Microscopy.
Of course what is encoded is actually force/velocity which in turn is inductively coupled out, but it is no surprise that simple optical scanning gives you mediocre results. Even 10x lower dynamic range requires 250nm optical resolution. It's doable, but not easy.
Thanks for the informative explanation! If say an 12-inch LP is scanned at 250nm optical resolution, what output digital image resolution are we talking here (in pixels)?
I wonder; could one project a horizontal line on a disc, a camera at an offset angle, and use the apparent deviations from a straight line for digitizing a record? I know there are full-analog laser players, but a full-digital solution might let you do fancy tricks to remove dust, particularly if you used multiple wavelengths of light, as slide scanners do.
Yes. But can you make vinyl records with laser printer? If you print on transparent, there are clearly ridges which could be enuff to guide a needle. I do not have record player anymore, so I cannot test this.
For some reason this reminds me of the Feynman article on HN recently ( https://news.ycombinator.com/item?id=26931359 ) - the enjoyment in pursuing something just because you think it would be fun.
And that's okay. Not every experiment needs to be a successful one or have perfect results. It's not like the author is so self-absorbed that they claim they are good. They explicitly say the decodings are "nearly-intelligible".
I can't tell the difference between the inability of this process to capture the audio and the distortion one normally hears introduced by MP3 compression. </s>
Edit: mono is radial only, not depth.