National Museum of American History curator Carlene Stephens examines a glass disc recording containing the audio of a male voice repeating "Mary had a little lamb" twice, made more than 100 years ago in Alexander Graham Bell's Volta Lab. (Source: Rich Strauss, Smithsonian)
Interesting from the standpoint of analog/digital resolution performance. It's been estimated that the equivalent digital channel spec. needed to equal "obsolete" 30 i.p.s. analog tape, which was the standard for high-quality recording back in the day, is a 500Khz sampling rate at 24 bits of TRUE resolution. The smallest signal modulations encoded in the groove walls of a vinyl LP are on the scale of a wavelength of visible light. 3D printing will have to go a long way to match that.
Greg, I agree. The videos showing the reproduced record were pretty impressive. The phonograph player reminded me of my Close and Play toy I had as a child. The limits of 3D printing applications are truly limited by one's imagination. Cool article Cabe!
Couldn't agree more. I can't wait to see what sorts of applications appear. Especially as the technology evolves toward improved resolution and a wider range of materials and post-processing capabilities.
It's one thing to replicate auto parts--it's another to revive history! That's a very cool application of this technology. And as an avid music lover who misses that scratch of vinyl, the idea that this could breathe new life into records also is appealing.
As someone who is just starting to rip their LP collection (I finished my first album just two days ago) I'm a bit perplexed. I understand the archival aspect of transferring old media (I wish I had something to scan records instead of playing them, an inherently damaging exercise). But I was expecting to read about someone printing a long gone DEVICE to play long obsolete media, not printing that obsolete media. Seems a bit of a waste, especially since printers are inherently rectilinear devices, not polar (as a record is), so getting a usable result would require a much higher resolution printer than currently exist.
Records (discs such as those shown in the article) use polar (radial?) coordinates (theta-radius). I would assume it would be extremely difficult to get adequate results printing a record in polar coord. using an x-y printer (and the article does imply this).
Interesting point about cylinders, though. Early commercial Edison recordings were cylinders. Of course, cylinders use both coordinate systems in three dimensions (fixed radius, with x axis and theta variables). You could print a cylinder by printing a flat sheet with x-y coordinates, soften the print and wrap it around a cylinder form. It would probably yield better results than a disk (except at the joint).
No, No, Rob. I was referring to planar discs, not recording cylinders, same as you.
Remember your coordinate systems from trigonometry class.
Polar coordinates are a system describing the location of a point from the origin by three angles and a radius.
Cylindrical coordinates are a system describing the location of a point from the origin by use of an angle, a radius, and a Z-axis displacement. This coordinate system (not the shape of the object) is much more appropriate for describing the groove geometry of a planar phonograph record. The angle and radius describe the location of the groove, and the Z-axis displacement describes the depth of the needle in the groove. It is the variation in depth (Z-axis) which stimulates the crystal or magnetic cartridge transducer, creating the sound.
In fact, a waveform of only the Z-axis sound would be a representation of the audio.
Polar co-ordinates (without further specification) is a 2D system, locating a point in a plane by angle and distance from a reference point. The other common 2D system is Cartesian co-ordinates which locates a point by distance from a reference in two predefined directions. There is also higher dimensional Cartesian and Polar systems.
It sounded from your description like you were trying to define Spherical co-ordinates, a 3D system of TWO angles and a distance. The two angles correspond to lattitude and longitude on a globe. Spherical co-ordinates is one of two common 3D polar systems, the other is cylindrical co-ordinates, a system of two distances and an angle.
There is a 3D system that uses three angles. It involves two predefined reference points on a predefined reference plane. The three angles are the polar direction from each of the reference points and the angle from the plane. A 3D system that involved THREE angles and a distance would be overconstrained.
BTW - Your description of Cylindrical co-ordinates was completely correct. I was referring to the description in the previous paragraph. It was your "polar" co-ordinates that I think you meant "Spherical" and put in an extra angle. It occurred to me after I posted that my reference was ambiguous.
Ahhhhh, Bach! (sorry, bad pun-ish MASH reference).
Yes some older recordings used the Z-axis to encode audio info but most use the radius (I believe "squiggles in the groove" is the technical term), so a simple polar coordinate system is usually sufficient. LP's/45's squiggle both sides of the groove independantly to encode stereo, so that does add a z-axis component.
All of this just shows how hard it really is to capture info from obsolete media, and how much harder it would be to "print" a record ("disc") with any usable fidelity.
The printed audio is only surface texture. The higher the resolution printer, the better the audio quality. I suspect that in the near future almost perfect copies could be made. Or perhaps like an LP printed with CD quality audio. Either way, the future looks good for keeping the LP record around.
To be completely honest, I like LPs, not just for their music quality, but the packaging is big. It's cool to see the pictures larger, it's a fun novelty. But with high bit rate audio files, that surpass CD quality and approach analog, I see no practical use for LPs anymore. (Maybe the hardcore DJ business?)Think of it like integrating a curve, eventually digital will match it so fine that the difference will be indistinguishable.
Plus, one speck of dust popping the sound of an LP ruins it for me. I have a few old Beatles records that have permanent tiny scratches, playback drives me crazy.
Cabe, this music lover has been hearing those arguments, and promises promises, for a couple decades. For some types of music, in particular the human voice, the sound simply isn't as good. I've been sorely disappointed on that end. OTOH, instrumentals, especially strings, are great or OK on a) CDs and b) a lot of high bitrate audio files. Regarding picture size, etc.--it was a real shock back in the day to get CD versions of LPs and not be able to read anything on the covers--or later, when an "album" was initially released as a CD, and the album cover content dropped to practically zero. OTOOH, now we sometimes get inserted booklets, which can hold a lot of info.
When CDs were just starting to get distributed several record labels simply mastered the CD from vinyl with a hefty low pass filter to kill the pops rather than digging the 2 track master out of the vault. it was a sin, considering the wonderful technology that was available, and my old vinyl copies were much better than the CD. I had a copy of "Layla" that was just terrible until they remixed the CD from the original 16 track in 1990. Geoff Emerick, made certain that he original masters were used for the Beatles material and now you can even hear the dust on the faders (rotary back then).
Not for me, your mileage may differ. I retired my vinyl years ago, and I'm a firm believer that the CD is king and that digital music reproduction gets a bad reputation because of squished down MP3s. Tape has way too much hiss, except when used with DBX or other companding. That said, I still love my old Fender tube amp, so I do believe in some retro gear.
Nevertheless, it is unfortunate to say, since 3D printing is based on digital signals, the LPs created are digital copies. In other words, less quality than they could be. In the case of preservation, It is good enough. Now it just seems silly to print an LP. I suppose it's a good option for those hipsters out there. It's all about image these days.
To get the latest engineering students' skills up to par, more colleges are turning to technology companies to get the best visual equipment in their labs for enhanced practical and theoretical teaching.
The Business Advantage Group recently released its 2014 Worldwide CAD Trends Survey, announcing both a prospective increase in the cloud-based CAD industry and the anticipated incorporation of 3D printing.
Autodesk, a leader in 3D design solutions, announced earlier this month that it has completed its acquisition of Delcam, a leading supplier of CAD/CAM manufacturing software, in its efforts to expand the companyís manufacturing software capabilities.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.