Analog Optical Recording

How is it substantially or materially different from a laser disc system? Is it a complete departure? It's hard to imagine how this would be an analog item. I'm not really sure the world is ready for another format. Seems like we're kind of burned out on all the format changes and that might be exactly why vinyl has come back.

To include Shrugg in this answer, no, this is nothing like laser disc. And I'll use this one to answer everyone else as well.

Not ELP, not LaserDisc, not designed to read existing vinyl. This would be an entirely new technique the details of which are dependent on X3 (can't type technical on this board so read that as Chi 3) the non-linear optical susceptability of a particular material. Exposure controls the induced change in the material and read back sees that change. Gents, I really don't wish to seem haughty or anything at all remotely like that as this business has always been a haven for some deeply fraudulent techno babble, but with PhD in Optics and Lasers and 24 years in designing lasers and optical systems for advanced defense applications, I have a few techniques in hand that have been proven and can be adapted to the task of analog recording.

The signal from the mixing board would modulate the laser, the laser would therefore modulate (through a Chi3 process) a material spin coated to a substrate. Readback would be accomplished via a laser diode illuminating the coated disc, the output of which would therefore be the modulated signal originally recorded. So it is pure analog. Anyone with a background in optical susceptibilities would immediately note that a Chi3 process is likely to yield modulation to the polarizability and therefore constrains the dynamic range to 90 degrees of polarization rotation. Two channels means that the net beam containing both information streams is a dynamic polarization ellipse and therefore easily read and deciphered back to a purely analog signal. It has also been shown as many as 40 years ago that the dynamic range of 90 degrees polarization rotation can be discerned down to 14 bit equivalent. That number is limited by the quantum noise (aka injection noise) of the photodetector. And photodetectors are WAY better than they used to be. I can buy photon counters (yep, detectors where the noise is so quiet they can reliably count single photons) for $50.

This brings us to Nat and Manfred's replies which are the most on point and present the greatest challenge. This requires a new physical media, likely about the size of a CD and able to contain about the same amount of music (roughly 40 min) in purely optical analog form. Writing a disc would be pretty close to the kind of process for mass production of CDs. You can dang sure write them way faster than you want to read them out. And the playback hardware would be good for only this. Simply laser diode as opposed to a fairly sophisticated laser to do the writing but it would all be optimized to read the OAR (Optical Analog Recording). Are there enough crazies out there to warrant the attempt?

I know you guys would pay $2k-$5k for the playback machine for your system. The bigger question is would you pay $40 for an OAR to get really pure analog recordings?

Nat and Manfred, good to hear from you guys again and thanks for chiming in. The last 6 yrs or so have been really difficult and busy as we in the high end laser business are reaching the long term goals of multiple 10s of kiloWatts for ship and airborne defensive systems. Directed Energy is going to work...it does work...but the physics are damn hard.
 
So it's analogue, for analogue's sake? I have to ask what parameters will it possess that will be vastly superior to what we have right now? Otherwise it is a tough to impossible sell. What aspect of sound reproduction is this idea advancing?

Half the capacity of the 35+ year old compact disc (you say 40mins)? A superior optical format in its twilight years, will people line up for another?

Entirely analogue. Really? No digital systems for focus, tracking, disc control. No track markers, time codes, nothing? That'll be fun to design and work on. Do you remember the entirely analogue servo systems in 1st generation CD players- sadly I do, horrible to work on. Do you just have a back and forward button or an analogue lever to physically re-direct the beam old-skool style?

What is the point of releasing 'really pure analogue recordings' of digital masters or material that never saw an analogue recorder in the first place?

The catalogue of 'really pure analogue recordings' is restricted to old master tapes or hipster recording studios with old analogue open reels or digitizing from vinyl.

A playback only format with discs costing $40, playable only on one machine is doomed to failure- sorry Eric.
 
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I`m think that pure analog is not possible in this condition. Chi3 process is analog tehnique but I dont understand how to convert light from sensor to analog audio signal without using any digital tehnique and also how to record analog music if you need to convert analog audio signal to laser beam?! Control laser beam mechanism with what, brushless motor and potentiometer?!
Sorry but you need to use something in chain with digital process...
 
So it's analogue, for analogue's sake? I have to ask what parameters will it possess that will be vastly superior to what we have right now? Otherwise it is a tough to impossible sell. What aspect of sound reproduction is this idea advancing?

Half the capacity of the 35+ year old compact disc (you say 40mins)? A superior optical format in its twilight years, will people line up for another?

Entirely analogue. Really? No digital systems for focus, tracking, disc control. No track markers, time codes, nothing? That'll be fun to design and work on. Do you remember the entirely analogue servo systems in 1st generation CD players- sadly I do, horrible to work on. Do you just have a back and forward button or an analogue lever to physically re-direct the beam old-skool style?

What is the point of releasing 'really pure analogue recordings' of digital masters or material that never saw an analogue recorder in the first place?

The catalogue of 'really pure analogue recordings' is restricted to old master tapes or hipster recording studios with old analogue open reels or digitizing from vinyl.

A playback only format with discs costing $40, playable only on one machine is doomed to failure- sorry Eric.
This sounds harsh, but I have to agree. Releasing a new format is an uphill climb, and consumers are notoriously bad at buying into the promising ones....just ask Sony. Beta vs VHS, cassettes over R2R tape and vinyl, CD over vinyl, now MP3 streams over physical media.

If rolling out a new format has any chance of survival it has to appeal to the recording engineers who will be the first to use it. Can the media be overwritten as reliably as tape? Is it user friendly? There are probably more technical questions that need answering than I know to ask, but if the industry doesn't embrace it there's little chance the consumer will.
 
I`m think that pure analog is not possible in this condition. Chi3 process is analog tehnique but I dont understand how to convert light from sensor to analog audio signal without using any digital tehnique and also how to record analog music if you need to convert analog audio signal to laser beam?! Control laser beam mechanism with what, brushless motor and potentiometer?!
Sorry but you need to use something in chain with digital process...


With all due respect, electro-optic modulation can be accomplished by any number of direct techniques including acousto-optic modulators, EO Pockels cells, and a half dozen more that are all exceptionally mature technologies. This is my area of professional expertise for 25 yrs.
 
This sounds harsh, but I have to agree. Releasing a new format is an uphill climb, and consumers are notoriously bad at buying into the promising ones....just ask Sony. Beta vs VHS, cassettes over R2R tape and vinyl, CD over vinyl, now MP3 streams over physical media.

If rolling out a new format has any chance of survival it has to appeal to the recording engineers who will be the first to use it. Can the media be overwritten as reliably as tape? Is it user friendly? There are probably more technical questions that need answering than I know to ask, but if the industry doesn't embrace it there's little chance the consumer will.

The challenges of new media formats cannot be understated. I believe I have agreed that is so.
 
I am fascinated but can't imagine it will have an easy ride to fruition. Thanks for posting it. I will be watching.
 
This would be an entirely new technique the details of which are dependent on X3 (can't type technical on this board so read that as Chi 3) the non-linear optical susceptability of a particular material.
It can be written properly, χ⁽³⁾.

The signal from the mixing board would modulate the laser, the laser would therefore modulate (through a Chi3 process) a material spin coated to a substrate.
A nonlinear susceptability induced change in the index of refraction is not permanent. Permanent change can be made, but χ⁽³⁾ is not the droid mechanism you are looking for.
 
The answer, unfortunately, is no.
The world has changed. These days most people seem to listen to music while doing something else, and usually either listen to compressed MP3 or just have the radio on in the background. Sadly, few people actually sit down in a quiet room with a dedicated hi-fi system specifically to listen to and appreciate music (their loss in my opinion). The number of people who have any kind of dedication to very high quality sound is likely to be even less. Although there has been a recent revival in the vinyl format, and CDs are still hanging in there, it still wouldn't justify the investment necessary to do what you are proposing.

One really odd thing is that in this 'on-line world' in which we now live, there are some people that now collect vinyl, but have nothing to play it on. There has been a resurgence in people buying vinyl because they like the look of it, and also because they like the idea of owning something physical with nice sleeve artwork, rather than having a invisible download.
 
It can be written properly, χ⁽³⁾.


A nonlinear susceptability induced change in the index of refraction is not permanent. Permanent change can be made, but χ⁽³⁾ is not the droid mechanism you are looking for.

I humbly bow to your greater knowledge of the text editor for the board. Equation Editor associated with Microsoft Office suite and embedded in any number of physical modeling software packages is an old friend but I didn't work very hard to find the best approach to using equational text here.

As for the usually temporary nature of induced higher order susceptabilities, you are again quite correct with the exception of a class of molecules which have been shown to structurally modify in response to the instantaneous field they are exposed to. These have been known for about 15 yrs or so within the chemistry and spectroscopy communities. It may not be a true χ³ (copy & paste does work however, therefore thank you) but it is hard to see the difference. Taking the view of the SHO for an outer bound electron, χ³ and other high order non-linear terms represent the driven oscillations of the dipole beyond the small angle approximation (Sin Theta ~ Theta). Linear optics is when you don't push the dipole too hard and you get linear response to the applied field. Push the field harder and you start to get higher order responses. Materials don't permanently change or embed that field information as a rule (and now we have to change that to "as a general rule") but this class of organo-silanes does indeed structurally embed the field information in a configurational change that sticks. Or more directly, you write a polarizability into the material as a function of the applied field. Very cool. It's this physical phenomenon that set me on this line of thought. Turns out these silanes are very easily thin-film spin coated on substrates. Now you can see how we are moving toward a coated spinning disc that has recorded two channels (S & P polarizations) simultaneously. Playback is easy. A true random state source will be decomposed into two polarization states, each of which can be individually read.

As others have pointed out, the problem isn't the tech. It is the introduction and adoption of any new format. I think in the above paragraph you can see the potential for low costs in both substrate and spin coated organo-silane so the physical media wouldn't be terribly expensive. Spin coating is a completely mature manufacturing process from the semiconductor world. The music could be written on the disc at many times the playback speed given that waveguide optical modulators are common in the 10's of GHz (or the fiber optic networks wouldn't work so dang good). The cost of the recording lasers per recording station would likely be in the $30k @ range but this is not excessive in the fixed asset capitalization given a sufficiently large market size for the end product. Playback is actually pretty simple and individual machines for home use would be well within the realm of medium to high end users and filter down market just as every other tech has.

It really comes to the impedance of people buying music on a new medium. And that is no trivial barrier to overcome. Powertech is likely correct. Then the question becomes can the economics be made to work out if one is only selling to a narrower enthusiast community.
 
If you used this format for a digital source/master how would it sound in comparison to a cd of the same source? In other words will and analogue playback of a digital source sound different that a digital playback of a digital source?

or...is what you are suggesting to be used predominately with recordings whose source is analogue? Which is where my interest lies. This, I think, has strong market potential. Of course if your mention of $40 a pop for an album is accurate it may take a while to gain traction.

Also, are these proposed discs single sided or double sided?
 
We had analog optical discs 40 years ago -- LaserDisc. And while better than VHS, its analog audio quality wasn't great, even with the addition of CX noise reduction, so within a few years they added digital audio to it.
 
If you used this format for a digital source/master how would it sound in comparison to a cd of the same source? In other words will and analogue playback of a digital source sound different that a digital playback of a digital source?

or...is what you are suggesting to be used predominately with recordings whose source is analogue? Which is where my interest lies. This, I think, has strong market potential. Of course if your mention of $40 a pop for an album is accurate it may take a while to gain traction.

Also, are these proposed discs single sided or double sided?

Single sided. Same time content of a double sided vinyl album, roughly 40 min, but all on one side.

If you used a digital master to record this, you would still have lost the relative phase that gets lost in digitization. This would be a purely analog source such as original master tapes, newly recorded master tapes that were not digitized in any way, or (and best in show....) direct to disc like the old Sheffield labs! Replication would be reading the original direct to disc and feeding that analog signal forward to multiple production writing stations.
 
We had analog optical discs 40 years ago -- LaserDisc. And while better than VHS, its analog audio quality wasn't great, even with the addition of CX noise reduction, so within a few years they added digital audio to it.

Why do you folks keep invoking LaserDisc? Of course this is nothing like 40 yr old laser disc technology. Jeez, you'd think the laser and optics field hasn't accomplished a bit of progress over the last 40 yrs. Guess you don't believe in fiber optics, networks, laser surgery, laser weapons development, or any of that jazz. Free your mind, man. The world has moved on significantly.
 
Maybe we need some more information on that new analog technology. Only information what we have now is that this new technology work on Chi3 principles and that this new analog technology have better sound then LP today with advantages on many digital formats.
So, put us in right direction and tell us some basic principles for that technology. How it work, what is media, how to control it, how... etc.... Dont worry we are all audio enthusiast, not researchers who work on new stealth plane.
 
I know you guys would pay $2k-$5k for the playback machine for your system. The bigger question is would you pay $40 for an OAR to get really pure analog recordings?

I agree with the first statement. My answer to your question is affirmative. I'm frequently paying 30 $ for new 180 gr LP reissues.
 
Technical issues aside (and probably off-target based on OldADC's background), this very neat solution is a technology/product in search of a problem, which never turns out well. Getting the industry to adopt a new analog format seems Sisyphean at best.

Maybe it's not a mass-market product, though. Maybe there is a niche for superb quality analog reproductions of high-quality analog sources - kind of extending the MFSL model to include new media. If the playback machine is priced like a moderate turntable + cartridge, maybe a small number of reproduction facilities (the expensive, industry-changing part) could put enough of just the right kinds of music out to those people who would buy into it for the superb reproduction alone.

Money talks. The rights holders get an opportunity to sell the same thing again, so there is motivation with enough of a market or a sufficiently low entry cost. Risk for the buyer to try a new format might be pretty low - using the razors abd blades model, presumably there is money to be made on each disc sold, so the players might even be sold at or below cost. Small production runs of hardware seem to be pretty feasible these days, so a small market might be feasible.

The question of course would be how small is small, and is it big enough :)
 
Maybe we need some more information on that new analog technology. Only information what we have now is that this new technology work on Chi3 principles and that this new analog technology have better sound then LP today with advantages on many digital formats.
So, put us in right direction and tell us some basic principles for that technology. How it work, what is media, how to control it, how... etc.... Dont worry we are all audio enthusiast, not researchers who work on new stealth plane.

Well, sir, with 20 posters on this thread, one would have to assume something like 5x that who are reading but not posting and with that number, there are likely at least 2 readers who are industry observers searching these threads using search engines tuned to find interesting IP or violations of their company's IP. Just a reality. It works that way in all tech industry these days. Based on that, I have revealed as much or more technical info on the concept that a reasonable care and concern for defensible IP would allow. You can't tell everything in public and then assert patent rights over open-source discussions. We'll just have to leave it at that. Regrettable in some ways but a business reality.

The rest of the discussion is more about price point, market sizes and segmentation, cost of capitalization, etc. And there are some very good pieces of the discussion in these regards.
 
I agree with the first statement. My answer to your question is affirmative. I'm frequently paying 30 $ for new 180 gr LP reissues.

I was in a record store the other day and say $30-$45 pricing for vinyl. I hadn't track new vinyl prices in a bit and was a bit astonished. The selection was clearly oriented toward people who would buy based on whatever perception they have of the superiority of analog and vinyl and the growing size of these selections would indicate that $40 is a tolerable price point. At least for enthusiasts. Thanks for chiming in.
 
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