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EMF

63.16.72.193
Posted on August 10, 2009 at 13:27:25
unclestu52
Dealer

Posts: 6982
Location: Hawaii
Joined: March 5, 2005
 I thought I'd start off a new topic instead of simply replying to another post in another thread (May's post to the thread below)

Electromagnetic force is one of the most misunderstood or perhaps, more appropriately, neglected factor in audio design. The electrical and magnetic fields are inextricably intertwined, but the magnetic aspect has been very much neglected for the most part. In an age where extremely powerful magnets are common place (neodymium and other rare earth metals), we take those powerful magnets for granted.

Still, since the interactions have been studied for many decades and mathematically plotted out, it would behoove us all to reexamine their effects.

one of the most significant tweaks I have employed in the past few years has been the Z-sleeves from the Z cable manufacturers. Mark has since retired and turned over manufacture to another builder but his z-sleeves which he describes as a modified zero gauss chamber are extremely effective and in placing the nickel plated sleeves over the speaker cables and interconnects, a tremendous increase in dynamics and resolution can be achieved. The fact that such a simple device can have such a profound effect on sound is indicative of the neglect with which we place on the magnetic fields being generated by any active signal.

If magnetic isolation works so well with cabling, imagine the effects on a circuit board, where adjacent traces carry so much other and often conflicting signals.

The use of magnetic devices, from transducers to motors further complicates the design and optimization.

Stu
RE: EMF, posted on August 12, 2009 at 04:46:23
May Belt
Manufacturer

Posts: 411
Location: Leeds UK
Joined: March 16, 2005
 Unclestu, can I mix a set of different experiences into one story to illustrate where my approach comes from and what has governed that approach.

You describe fitting Z-sleeves over speaker cables and interconnects, and you go on to describe how
>>> "a tremendous increase in dynamics and resolution can be achieved. The fact that such a simple device can have such a profound effect on sound is indicative of the neglect with which we place on the magnetic fields being generated by any active signal." <<<

A very good description of what you, so obviously, heard !! But one point I would like to raise at the beginning. Your explanation for the 'effect' is a magnetic explanation.

Let me say (hypothetically) that you fitted the Z-sleeves one Tuesday in March. Now, the Z-sleeves cannot have ADDED additional information in the form of "better air, sparkle, transparency, openness, imaging, soundstaging and most importantly, naturalness and musicality, not to mention bass improvements." over and above what was already available on the audio signal, they can only have REDUCED an adverse effect allowing you to now hear "better air, sparkle, transparency, openness, imaging, soundstaging and most importantly, naturalness and musicality, not to mention bass improvements." (or your own description of a tremendous increase in dynamics and resolution) !!

But, logically, hearing this happen one Tuesday in March means that the day BEFORE, you had NOT been aware that there was even ANY adverse effect happening - until, that is, you fitted the Z-sleeves on the Tuesday and, on hearing such an improvement, THEN appreciated that there must have been something adverse happening on (with) the speaker cables or interconnect cable prior to that Tuesday. And, if you had had those cables the week before, the month before, the year before then that means, logically, that all that time you had had those cables, you had not been aware (soundwise) that there had been any adverse effect present !!!!

One crucial thing. If you could gain an improvement in the sound of "a tremendous increase in dynamics and resolution" AFTER fitting the Z-sleeves that Tuesday in March, then PRIOR to fitting the Z-sleeves you HAD NOT been 'hearing' just what those cables were capable of, just what your CD player had been capable of, just what you amplifier had been capable of and just what your loudspeakers had been capable of producing !!!!!!!!!!

Now, experiencing that improvement in your sound by fitting the Z-sleeves, you tell other people who you think might be interested. Other people DO hear what you had heard, some, though, did not hear any change in THEIR sound. They, therefore, say that you heard what you heard because of auto-suggestion, the placebo effect etc or that your NEEDED the actual 'ritual' of fitting the Z-sleeves to be able to relax more so that you can 'hear' what others can hear quite naturally without having to carry out the same 'ritual'.

With their experience (of not hearing any changes after carrying out the 'tweak' you had suggested), those people cannot therefore go along with the (logical) concept (which you, me and others had been made to realise because of the experiences which have happened to us) that there could be adverse effects, present either with cables, with interconnects, with equipment or with the environment which one may not be aware of until it is drawn to our attention because of what has just been done................. !!

You now go to a friend's house and take some Z-sleeves with you because you would like your friend to experience the improvements you yourself have experienced. You listen to his audio before suggesting fitting the Z-sleeves. You are not enamoured with his sound but before you can make your suggested changes he says "Oh I would just like to first try this chemical which Dr. Joe Bloggs has sent me to try before we fit the Z-sleeves." He applies, as per instructions, the chemical to the plastic outer insulation of an interconnect. You both listen.
You, Unclestu, hear practically identical improvements in the sound "better air, sparkle, transparency, openness, imaging, soundstaging and most importantly, naturalness and musicality, not to mention bass improvements." (or your own description of a tremendous increase in dynamics and resolution) as you had heard with the fitting of the Z-sleeves on YOUR interconnect !!

But the chemical being used is not magnetic and therefore cannot be having a 'magnetic' effect or be 'dealing with' a magnetic problem and yet it is having a similar effect on the sound as the Z-sleeves had !!!!!!!!!!!!

You tell others of this latest experience with Dr. Joe Blogg's chemical. Others try this also and 'hear' similar improvements as you and your friend had heard. Some others, also try Dr. Joe Blogg's chemical on the outer insulation of their interconnect but hear no improvement in their sound. They therefore conclude that the only reason that you and your friend heard improvements when using Dr Joe Blogg's chemical was because of auto-suggestion, the placebo, etc or because the process of carrying out the 'ritual' of applying the chemical enabled you and your friend to relax and hear more of the information which they can hear naturally without carrying out any such similar 'rituals'!!!

But, Unclestu, you would now have a problem. You would have heard similar improvements in the sound taking place, on similar cables, but from two completely different techniques. !!

If you had ONLY heard the effect of the Z-sleeves, then you would continue to use a 'dealing with magnetism' explanation. If you had ONLY heard the effect of Dr. Joe Blogg's chemical applied to the outer insulation of a cable, then you would continue to use a 'dealing with static' explanation. But, you have heard BOTH give a similar improvement in the sound of "better air, sparkle, transparency, openness, imaging, soundstaging and most importantly, naturalness and musicality, not to mention bass improvements." (or your own description of a tremendous increase in dynamics and resolution). So, you now have a problem and have to look elsewhere (further) for an explanation which would (could) explain BOTH events !!!!

You, obviously, MAY still wish to continue using both magnetic AND static explanations to deal with the two events but I would like you to consider one common denominator.

If you already have knowledge about polarities, then you can see a 'common denominator' !!
A magnet is a polarised object. A battery is a polarised object and such as SOME chemicals and SOME crystals can have a pronounced polarity !!!!!!!!!!!

So, could polarity be an issue ? Could polarity be the common denominator? Yes, electro-magnetism COULD be an underlying basic cause, I am not asking you to abandon electro-magnetism - I think it is as important and as neglected an area as you do - and may be the cause of creating an adverse polarity in the first place !! Could a specific polarity be what is causing an adverse problem ? So, could all those different things (magnet or chemical or crystal) 'somehow' be 'having an effect and altering the adverse polarity sufficiently to change the sound' ?? Could applying a polarised object (in the form of a magnet) alter an effect caused by an induced polarity and, similarly, could applying a chemical with a pronounced polarity alter an effect caused by an induced polarity ?

Let us look at chemicals.

For example, human tears are strongly electro-negative. Fluorine is strongly electro-negative and surprise, surprise, what do we have as one of audio's favourite insulation materials (from a sound point of view) - why PTFE - where the F in PTFE is fluorine !!!!!!!!!

Could such as the Nordost ECO 3 chemical (recommended for applying to the label side of CDs, to the labels of LPs, to the outer insulation of all cables, including AC power cables) NOT be 'dealing with' static as is the explanation put forward by Nordost but is 'dealing with' an adverse 'polarity' problem on the cable etc ? Does Dieter Ennemoser's C 37 lacquer improve the sound because it is 'dealing with' resonances or could it be 'dealing with' an effect caused by an adverse polarity ? Could aiming a hair dryer containing tourmaline balls at a CD and improving the sound from a CD be 'dealing with' some effect caused by an adverse polarity ?

Ditto applying a demagnetiser to LPs and CDs ? And, as I understand from people's experiences, to cables ?

Some crystals have a definite polarity !!
Could the (reported) effect on the sound of directionality in some wires be because of the creation of a particular adverse polarity ?
Is the technique used by the Shakti Stone device NOT creating a counter energy to the existing electromagnetic field and stopping this field doubling back on itself and interfering with the audio signal BUT by the Shakti Stone circuitry creating a counter to an adverse POLARITY created by the existing electromagnetic field ? The end result (an improvement in the sound) would be the same but it would be a different way of looking at it - adverse polarity versus adverse magnetism being dealt with ? This approach would explain so many similar effects by so many other dissimilar 'tweaks' that could not possibly be regarded as 'dealing with magnetism'.

ALL completely different techniques but giving similar results - similar DESCRIPTIONS of the improvements in the sound !!

So, there must be a common denominator somewhere but NOTHING whatsoever to do with auto-suggestion, the placebo effect, etc, or merely "performing a ritual" or "carrying out remedial actions" !!

Now, let me take the story further because it becomes even more complicated.
You are reading an article on plants and this article describes how a certain plant produces a specific chemical when under stress !! This 'rings a very loud bell in your head' because months previously, completely by chance, you had completely ruined your sound by applying a chemical to try to remove a stain on a coffee table. You had no explanation as to why your sound should have been so spoilt, only that it had been !!! Now, on further investigation, you discover that the chemical you have used on the stain contained, as one of the ingredients, the very chemical now being named, in the article, as a 'stress' chemical produced by plants !!!!

You HAVE to ask yourself the question "Could it have been me (the human being), who had 'sensed' the presence of that 'stress chemical' and that I had gone under tension myself because of 'sensing it' ?. And, could THAT tension, caused by the EXTERNAL 'stress' chemical in the room have caused the 'sound', or the way I was resolving the sound, to be so much 'worse'?"

Then, Unclestu, if YOU would know how to permanently polarise objects in a beneficial way, if YOU would know which chemicals have specific polarities, if YOU would know which chemicals are the opposite of 'stress' chemicals, when YOU would know these things, then there opens up (to use an expression) a whole new ball game !!

THIS extension to the story now brings in the overall effect, on the human being, of the modern listening environment !!!!!!!
Another long story !!!

>>> "Where I believe we still have a lot to learn is the effects of magnetic interference with adjacent circuits and dielectrics. We know there is an effect but we do not know the degree to which that interference will generate audible artifacts." <<<

How true, Unclestu !!! But, again, the problem I have with your approach is that you want to consider the problem (and the solution) to be wholly within the technical field (i e concerned solely with affecting the audio signal or the acoustic air pressure waves). And that is also the problem I have with rick m. He also seems to want the problem to be solely an engineering problem and the solution to be solely an engineering solution. I do, however, appreciate that both you Unclestu and rick m would be far more likely to nudge the world of audio forward than someone with a dismissive approach !!!! You, Unclestu, do NOT have a dismissive approach. Anyone who can say the sentence "Where I believe we still have a lot to learn" just cannot have a dismissive approach. I personally would just add a few words to that last sentence "and a lot to learn about the effect of our modern environment" !!!

To make reference to the thread on "Fuses" currently on General Asylum. This thread is taking the USUAL direction i.e BOTH sides - 'for and against', 'measurement versus listening', 'cryogenically treated and/or directional effect' but which you, Unclestu have stated what you have heard - "In my experimentation of fuse directionality, differences were clearly audible".

It really IS disheartening to read another (stated) 'professional' say the following :-

>>> "Fuses are not polarized parts. If you hear a difference between a fuse one way vs. the other, you can likely conclude that you can't trust your ears.
Yes, I am disputing what you are hearing. Your claim is like somebody saying you can put a magnet in your gas tank and see 10% better gas mileage.As for fuse directionality, they are symmetric (speaker wires often are not) and this is like saying that water flows through an extruded PCV pipe better one way than the other.
If you are not willing to submit yourself to a DBT, your claim is meaningless (study Fisher/probability/statistics) Without some kind of checks/balances system, we will all end up with Timex clocks and jars of crystals all over our listening rooms." <<<

So, Unclestu, when one can apply a particular chemical to such as the body (glass ?) of the fuse OR colour both end faces of the end caps of the fuse with the colour Violet or Purple and gain an improvement in the sound, then what would be YOUR explanation ?

Regards,
May Belt.
RE: EMF, posted on August 12, 2009 at 12:58:41
unclestu52
Dealer

Posts: 6982
Location: Hawaii
Joined: March 5, 2005
 Well, maybe yes, but bear in mind I have experimented with my sleeves, dismantling them, careful examining them and reassembling them. Along the way using standard laws of physics I elected to make a few improvements: replacing the brass sheet with copper tape, for example and achieved what I believe the theoretical results would have predicted: a "faster" sounding device which seems to have accelerated the signal in the cabling (that along with a couple of mechanical modifications, of which I'd rather not reveal at this point).

The function is not so much as keeping out the external magnetic fields although I am sure that may be a factor, so much as to propagate the magnetic fields generated within the cable itself. Where something like a ferrite use magnetic fields to constrain the signal going through it, the magnetic fields generated like nickel and moves through it faster than air. That fact is no secret among magnetic researchers however, and it is a well known fact that magnetic fields would rather travel through a ferrous object.

I have not experimented with coloring on a fuse. I would rather not comment unless I have played around with the concept more fully.

That being said, colors and simple fact that dye lots employ different chemicals in order to create the colors we see certainly can conceivably affect the performance of an object so colored. An interesting experiment would be to simply switch your light bulbs in a room to a colored one to verify if the color itself is the causality or the coating that a pen lays on an object is the root cause.

In experimenting with light, I have definitely noted that tubes respond to variations in light intensity. They sound " fuller" and warmer in the absence of light' perhaps a partial explanation for why things often sound " better" when listening in the dark. In addition I do note that in placing ferrite beads and cores upon my lamps and such, I can hear a definite improvement in sound, leading me to conclude, that, in addition, lamps generate their own kind of noise and emit it into your power grid. Differences are small, but they are cumulative. Simply placing ferrites on one power cord of a lamp may not accomplish much, but placing them on all non audio devices in your home certainly helps.

In experimenting with the colors of electrical wire insulation, I learned quite a bit. The base color of the insulation ( plastics, for the most part, is a milky semi transparent substrate. Every other color, including clear involves additives of some sort, which can also be construed as an additional ingredient, having some influence, however, small on the electrical properties.

Finding a company to humor my experimentation was a bit difficult, particularly as I am an individual not a well financed research facility. I'm sure you can appreciate that fact, too. At any rate, I found that Kimber Kable was quite responsive to supply me various pieces of wire from their available stock. They can make the PBJ in a choice of 8 colors for example and yo can even order individual colors separately so long as you order a small spool of 250 feet ( they made an exception for me and sold me 100 foot spools of various colors). More importantly, they confirmed that each batch used the same metal from the same dies, and that the insulation was theoretically the same ( teflon composite) with the only difference being the color. T Not being able to actually oversee the manufacture, that was quite important for me, although I had also used a brand of hook up wire to make my preliminary observations.

Reds have nice midrange. Blues have good bass. The clearer the insulation the more neutral the sound, and other lighter colors are similarly inclined: gray, white, yellow. Black,as I have long maintained, sounded definitely muddy and smeared. Here, though the effect is definitely doe to the slightly different dielectric constants created by the addition of the dye lots. I do realize that electrical insulations do NOT necessarily use the same dye lots as artist's paints use, but examining the composition of artist's paints is instructive.

You have Cobalt blue, cadmium red, and many others which hint at their composition. I do believe these additives do subtly affect the performance of the wire insulation by affecting the electrical inductances generated within the the conductor itself.

Stu

RE: EMF, posted on August 14, 2009 at 08:48:35
May Belt
Manufacturer

Posts: 411
Location: Leeds UK
Joined: March 16, 2005
>>> "In experimenting with the colors of electrical wire insulation, I learned quite a bit.
Every other color, including clear involves additives of some sort, which can also be construed as an additional ingredient, having some influence........
More importantly, they confirmed that each batch used the same metal from the same dies, and that the insulation was theoretically the same ( teflon composite) with the only difference being the color." <<<

I am SO pleased you described your experiences with the different coloured wire insulation. I sometimes wonder just HOW much (or how little) listening experimentation people in the world of audio do, or have, carried out !!

Way back at the end of the 1970s, we were preparing our new Orthodynamic speaker Tower, ready for a Hi Fi Show. This Tower consisted of 108 Orthodynamic drive units and these drive units would be connected 'in series' and 'in parallel' to bring the whole thing down to 8 ohms to match into the amplifier. For ease of manufacture, we had worked out the colour sequence (of the insulation of the wire) we were going to use for each set of drive units wired 'in series', what colour sequences to use for wiring each set 'in parallel' and what colours we would use to link complete sets of drive units !!!! We ordered a high specification wire to be manufactured and - just as you had done - asked for reels of exactly the same specification wire but with different coloured insulation !!

What we found was that the colour sequence WE had decided on, when it came to the actually wiring of the sets of drive units, it was the SOUND of each colour which became the deciding factor in which drive units should be wired in which colour, which colour should be used to link those sets and so on. This, as you can imagine, was quite nightmarish at the time but what it DID do was to POINT OUT to us the significance of different colours and their SOUND !! So, when we eventually ( a few years later) bought a CD player and a few CDs and we saw the coloured art work on the labels of the CDs, we were already aware just how significant were colours to sound !!

We told others of our findings and some of them did their own investigations.
As I described recently on another forum (Stereophile Forum), in 1987 Christopher Breunig the Musical Editor of Hi Fi News published an article describing an experiment he had carried out. He took two identical CDs and, keeping one as the control, removed all the printing from the label side of the other CD and then listened to both. He judged the CD without any printing on at all was the best sounding CD.

Shortly after that Laszlo Darvas, the Editor of the Hungarian Hi Fi Magazine went even better. He got a Hungarian CD manufacturer to make him 10 identical (musicwise) CDs. To have one of the CDs exactly as was sold to the public but to have the other nine CDs with exactly the same art work printed on the label side but with each one printed in a different colour. He then listened to each of the 10 discs and graded them (soundwise) according to the COLOUR of the printing on their label side. This result he published in his magazine - with a rough translation I think the Hungarian article was called "It is all in the painter's brush".

Then, later, someone introduced a Green Pen with instructions to mark the extreme edge of CDs with this green pen to give an improvement in the sound. The usual explanation put forward for the effect was 'something to do with reflection or refraction of the laser beam'.

But, the best 'sounding' colour is Violet or Purple and you do not need to mark the entire edge of the CD, you only need to make a 1 cm mark to get an improvement in the sound !!

However, the crucial thing is not even that !! Because you can make an identical 1 cm mark with the colour Violet or Purple on the extreme edge of a VINYL disc, on the outer edge of an audio tape, on the outer edge of a video tape and on the end faces of the end caps of a fuse and gain an identical improvement in the sound from doing all those !!! And, there IS NO laser beam involved in any of those things !!!!!

>>> "An interesting experiment would be to simply switch your light bulbs in a room to a colored one to verify if the color itself is the causality or the coating that a pen lays on an object is the root cause." <<<

A very interesting experiment indeed, Unclestu !!! Try different coloured light bulbs, listen to each one in the listening room, grade them (soundwise) best to worst, then take the WORST sounding coloured light bulb and apply a specific chemical to it's glass. Then listen to it. It will NOW be the best sounding light bulb !!!!!!!!!!!! Irrespective of the fact that it had been the worse sounding colour !!!!

>>> "In addition I do note that in placing ferrite beads and cores upon my lamps and such, I can hear a definite improvement in sound, leading me to conclude, that, in addition, lamps generate their own kind of noise and emit it into your power grid. Differences are small, but they are cumulative." <<<

>>> " in addition, lamps generate their own kind of noise and emit it into your power grid." <<<

But, if you find which is the lamp which you think is generating the WORST kind of noise and emiting it into the power grid, if you apply a specific chemical to that lamp, it will be the BEST sounding lamp !!! Irrespective of how much NOISE you might think it is emiting into the power grid !!

>>> "Simply placing ferrites on one power cord of a lamp may not accomplish much, but placing them on all non audio devices in your home certainly helps." <<<

I DO NOT dispute the fact that a ferrite can have that effect, but, in exactly the same way as I describe above, if you apply a specific chemical to the outer insulation on ALL the NON audio power cables in your home, you will gain an improvement in the sound with each application. And, the chemical (or chemicals) are NOT ferrite !!! So, the chemicals AND your experience with ferrites are obviously doing something similar. It is WHAT similar thing which is the million dollar question !!!!

Nordost explain THEIR chemical as 'dealing with static' but I would challenge THAT explanation also.

God, it is good to talk to someone who is not dismissing it all as 'ritual' or 'remedial' !!!

My experience has shown that if someone STARTS with the experience of colours influencing sound, then they will think colours, sight, dyes etc and if nothing else 'rocks that explanation', then they will continue to think colours, sight, dyes etc.
If someone STARTS with the experiences of magnets, ferrites etc influencing sound, and if nothing else 'rocks that explanation', then they will continue to think magnetism etc.
If someone STARTS with ther experience of chemicals influencing sound, and if nothing else 'rocks that explanation', then they will continue to think 'static' etc.

But, I am sure, Unclestu, YOU will have, at times, during all your investigations, HAD TO re-think, re-evaluate some previous explanation and re-adjust them (or even completely overturn them) in the light of new experiences.

And, if some people have had none of those experiences, they end up saying something like the comment in July 2009 on the Stereophile Forum, referring to the article on "The Greening of SACDs, (gulp) CDs and other digital madness" by Teresa Goodwin in the June 2009 issue of Positive Feedback Online.

>>> "Nah, they were smart enough to presume that if you just remaster it, goosing the bass and treble a bit, slap a green label on it and put out a press release, every self professed whacked out 'advanced audiophile' like Teresa Goodwin and, ahem, others will start runnin' round the internet claimin'… I told you so!

Sheesh, you folks will believe anything. It's not Sony's CD's. It's their SACD's. Now I wonder why that is?" <<<

STILL - 20 to 30 years after it was first reported (AND investigated by many) that colours are significant regarding sound, there is STILL the dismissive attitude of "you folks will believe anything" !!!!!!!!

Obviously, that is someone's opinion and they are entitled to it. But, what it shows is just how difficult it is for people who have NOT experienced what many others have heard, to understand what they are talking about !!

Regards,
May Belt.

Colors, posted on August 14, 2009 at 23:24:08
unclestu52
Dealer

Posts: 6982
Location: Hawaii
Joined: March 5, 2005
 I don't doubt the influence, but colors play different roles in different application,

In the case of CD's, colors are important simply because of the physics involved. Nothing mystical nor magical. We see colors simply because the wavelength of light associated with that color means that that color bandwidth is being absorbed by the product colored that way, and the other wavelengths reflected.

Thus a blue object, which corresponds roughly to 420 nM means that other wavelengths are being reflected. Red, IIRC, lies roughly about650 NM or thereabouts. Considering that a laser is a monochromatic light source, It is obvious that certain colors will absorb stray and scattered laser light.

In my admittedly simple and not very thorough investigation of the photo electric effect on vacuum tubes, it is interesting to note that the most noticeable improvement occured with LEDs colored roughly the same hue (yellow/orange) as the light emitted by the glowing filaments. It would mean that the photon intensity would be seemingly increased at that frequency spectrum.

In examining the color spectrum of a rainbow: the violet/ blues lie at the highest frequency of visible light, Te reds at the lower frequencies, of admittedly a very small spectrum of the electromagnetic bandwidth. Color itself is more indicative of the state of energy being worked upon. It would then be an indicator in addition to the actual work it does upon the energy output itself.

Within the insulation of the wire, the color has more to do with the dye lot composition, and it is this slight chemical change which creates the the effects on the generated EMF field. While the various colors induce a more subtle change in sound the use of carbon produced blacks have an extremely detrimental effect, simply because the carbon is very slightly conductive.

It's being adjacent to a copper conductor can easily be viewed as being potentially a issue in producing a coherent signal flow down that conductor. The view that the use of carbon fiber as a conductor is drawing interest simply because physicists view the carbon nanotubes, 2 to 4 nM in diameter, as being so small that only one, maybe two electrons can flow along the nanotube, essentially creating a very coherent electron pathway. It's higher resistance can be countered by simply paralleling many strands since the nan tubes are so minute themselves.

In my thinking, an understanding, even a theoretical one, helps the promotion of new ideas and products, and application also. This certainly creates a concrete advancement of the art and technology of audio. It leads to replicable results and sets off thinking for potentially other application.

Stu

RE: Colors, posted on August 15, 2009 at 10:56:11
geoffkait
Manufacturer

Posts: 3515
Location: northern Virginia
Joined: August 23, 2000
 If you write your name on turquoise paper with a red pen your name will appear black because red and turquoise are "complementary colors." This is apparently the reason green or green-blue pens on the outer edge of CDs work.. But try to explain why violet/purple pens work as well or better than green or green-blue on the CD edge.

Then there's the color(s) of the CD label to consider.

PS blue objects appear blue because the wavelength of blue is reflected. Blue's complement will absorb blue light. Is it yellow? That's such a bright color :-)

Thanks for the tutorial, anyway. :-)
RE: Colors, posted on August 19, 2009 at 22:37:17
Ugly
Audiophile

Posts: 1421
Location: Des Moines, WA
Joined: August 22, 2006
 "But try to explain why violet/purple pens work as well or better than green or green-blue on the CD edge."

Not an optics expert but I can't help but wonder if this explains it...

Perhaps since our eyeballs are heavily biased to detect green better than other wavelengths perhaps we see things differently than a more redward (is that a word?) biased silicon photodetector would. IOW perhaps the colors our eyes suggest are complementary are not the same colors that would appear complementary to an eyeball (photodetector) whos sensitivity was shifted from what humans see best, green, toward the infrared cd laser band the cd player photodetector would be most sensitive to.

RE: Colors, posted on August 20, 2009 at 14:42:56
geoffkait
Manufacturer

Posts: 3515
Location: northern Virginia
Joined: August 23, 2000
 I would wish to like your theory, but the human vision doesn't enter into the equation in this case. The CD player's photo detector wants to see near infrared/red light and will detect both the direct reflected laser light and scattered light. This is why the complement of red - which is blue-green - is effective, since it absorbs (some of) the scattered background light. But the color purple is mysterious because it is not red's complement, but yellow's. I.e., doesn't make sense.

RE: Colors, posted on August 20, 2009 at 20:53:02
Ugly
Audiophile

Posts: 1421
Location: Des Moines, WA
Joined: August 22, 2006
 "I would wish to like your theory"

I appreciate your graciousness. Thanks.

My confusion stems from my assumption that what we know as color complements were presumably originally defined using eyeballs.

Could it be that colors combos which absorb (reflect less well) in the bands apparent to an eyeball may be reflecting heavily in a band not so visible to an eyeball such as infrared which the cd photodetector detects readily?

and the inverse question which goes with it...

Could color combos which are more reflective to wavelengths that eyeballs have hotter response to potentially be more absorptive to the wavelengths the photo detector responds well to?

IOW maybe the colors we've defined as complementary using our eyeballs are not the same colors which appear as complementary to the cd photodetector.

Sorry if I am being thick.

Your conclusion is correct., posted on August 26, 2009 at 12:01:43
rick_m
Audiophile

Posts: 2538
Location: Oregon
Joined: August 11, 2005
 "My confusion stems from my assumption that what we know as color complements were presumably originally defined using eyeballs."

Your assumption is entirely correct, complementary colors ONLY exist as an artifact of the eye and brain. The EM spectrum is continuous.

The characteristics of dyes vary all over the place. If you want to know what the transmission/reflection characteristics of it are at a particular frequency the easiest thing is to measure it there or illuminate it with a black body source hot enough to emit through the region and look at it with a diffraction grating via eye if in-band (for the eye).

I used to do photography as a hobby and this stuff takes on a poignant focus in that realm. My original enlarger didn't have a color head and you had to use filters to adjust the color balance. It was insane. What made it so was that the transmissive attenuation of the filters went to pieces at IR and the stinking paper was responsive to IR. It was easy to spend an evening just doing one print. After I got a dichroic color head with a heat mirror sanity prevailed.

The only thing that matters to a sensor with monochromatic source in an isolated environment (a CD drive in a light-tight box) is what happens at the source frequency. If purple helps then it probably is having an effect at that frequency. May, I know, there may be a whole other realm, but I can only speak to that which I understand a little. The reason we put red lenses into handheld barcode scanners is to get a better S/N by trying to isolate the sensor's environment so that it only sees the laser's reflection. Common knowledge...

Of course, you ain't being thick, you're being scientifical.

Rick

RE: Your conclusion is correct., posted on August 28, 2009 at 08:54:22
May Belt
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 >>> "If purple helps then it probably is having an effect at that frequency. May, I know, there may be a whole other realm, but I can only speak to that which I understand a little." <<<

>>> "but I can only speak to that which I understand a little." <<<

I don't have any problem with your last remark, rick m. Surely we are all at that point with 'something' at 'sometime' in our lives ? But, rick m, you have stayed only on the subject of CDs and applying the colour to CDs.
If the colour Purple, when applied to the edge of a CD, improved the sound, then Yes, it would just be another variation of the effect when the colour Green was applied. It is when it DOES something ELSE, completely unexpected, (so the explanation cannot be auto-suggestion, the placebo effect etc. Etc) which 'throws the spanner in the works'. When you can get similar improvement in the sound (similar to the improvements in the sound from applying the colour Purple to the edge of a CD) by making similar markings with the colour Purple to the outer edge of a VINYL disc, to the outer edge of an audio tape, to the outer edge of a video tape, to the end faces of the end caps of a fuse - THEN you have to "consider a whole other realm". The existing "understanding" of colours is then inadequate !!!

And, because it is 'sound' which is involved in all those instances I have quoted - NOT what we are seeing !! then you have to open out your thinking - away from 'seeing' colours !!

Are we (human beings) sensitive to the different colours OTHER than with our sight ?

If the scientists are correct that each colour is a different frequency, could we be sensitive to the different 'frequencies' ???

If the scientists are correct that every colour (therefore every frequency) is absorbed by the object EXCEPT the one colour (the one frequency) we can SEE, then are we (human beings) sensitive to that one FREQUENCY which is NOT absorbed ??? Do we react differently to different frequencies ?

Is that how colours can "affect" sound ? Not because of their different colours but of their different frequencies ?? And that we (human beings) might be sensitive to (and can detect) the differencies in the different frequencies on the different objects ?

Regards,
May Belt.

RE: Your conclusion is correct., posted on August 28, 2009 at 09:44:37
rick_m
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 Hi May,

Color is frequency(s). We directly sense radiation from IR via the skin to Violet via the eye. I don't know of other mechanisms unless the energy of the radiation is high enough to cause damage. But, of course that doesn't mean that they don't exist. However, to the best of my knowledge I've never experienced any.

I was trying to reinforce the notion that perceived color can easily be spoofed if the source isn't continuous and it's especially hard to predict what is happening out of band (IR) where CD playback lasers run.

When this was a big thing a friend told me that using a certain marker from the hobby shop worked well, I think the "pigment" was carbon black. I carefully tested the result and found that there was none. I suppose it might have been a different story with a different color but I doubt it, it's much more likely to be an artifact of the player or disk IMHO and apparently the ones I used for testing didn't care. That's just a single, non-predictive data point of course.

Regards, Rick

RE: "I suppose it might have been a different story with a different color but I doubt it", posted on August 28, 2009 at 15:38:20
geoffkait
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 I can say from much experience (and the experience of many others) that the color blue-green in the immediate vicinity of the CD laser works extremely well. Much more so than around the edge of the disc, apparently because the CD edge treatment is only partially effective - much of the damage (by scattered light) is already done. This particular color is very effective for absorbing stray scattered light that could otherwise find its way into the photodetector, which of course is located directly next to the laser. I estimate the performance improvement for most players using this technique is in the range 40-100% in fact.

Now, the color purple around the edge of the disc is also interesting, but why I do not know as there is no color theory to account for it.

RE: "I suppose it might have been a different story with a different color but I doubt it", posted on August 28, 2009 at 16:19:01
rick_m
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 Geoff, isn't the important thing it's absorption characteristics at the laser frequency (IR)? I'm not sure how reliable visual color is as an indicator. I think 'color' theory is really 'eyeball' theory. But it seems logical that reflective green may be OK since it works by absorbing the red and blue regions. Really depends upon it's bandwidth. Carbon black seemed like a good candidate color wise, but I really didn't pursue it.

Location wise, that makes excellent sense to me now that you have pointed it out. I'll keep it in mind, thanks for the tip.

Another might be the area above the disk, they pass quite a bit of light through the metalization. It's always bugged me that I could read the printing from the bottom of most disks and wondered why it didn't become an error term. Maybe that's part of the improvement with mats, the top would be more uniform if they had the same absorption as the printing.

I'm confident, now that CD's are being replaced by downloads, that they will finally be perfected. That just seems to be the way of it...

Rick

Speaking of carbon black. Has anybody tried some Sharpie?, posted on August 29, 2009 at 10:08:53
Ugly
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 It's not really a matte finish but I've had some success with the stuff.

I have used sharpie as an enhancement to an IR position sensor piece my group dreamed up. Being the electrical guy it became my responsibility to get the rig performing its best. Sharpie-ing became part of the sensor final prep during assmbly. It seemed to have a very strong effect in the band we were using it at which I want to say was in the 950nm range. Testing showed that it is surprisingly rugged over time and exposure. I can oly imagine the potential chaos that would ensue at my old company if sharpie ever changes its formula.

RE: Speaking of carbon black. Has anybody tried some Sharpie?, posted on August 29, 2009 at 10:57:55
rick_m
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 I just paddled down to the garage and sure enough I still have the marker. It's a Testor flat paint, black. It is also quite dried out after laying around for nigh-on twenty years.

I bet we could rig up an easy absorption test. If they make those angled surface sensors with a linear detector in them it shouldn't take much to at least get a comparative measurement of the absorption of various markers and material at IR.

It occurs to me that one of the things that might be happening with the violet marker that Geoff was talking about is that rather than acting as an absorber it may be functioning as a coating to improve the impedance match between the CD edge and space which would help get energy out of the disk itself.

Most of this stuff seem rather measurable if any of us cared enough to go to the effort. But it's more fun and a lot easier to simply curl up with the laptop and speculate. And make bad puns. What we need is a troupe of technicians to look into this under our august guidance.

Rick

RE: Speaking of carbon black. Has anybody tried some Sharpie?, posted on August 30, 2009 at 12:04:15
Ugly
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 "I bet we could rig up an easy absorption test. If they make those angled surface sensors with a linear detector in them it shouldn't take much to at least get a comparative measurement of the absorption of various markers and material at IR."

It would be nive to have a continuously variable frequency source for this kind of testing. Is there such a thing? I'm not sure which angled surface sensors you are referring to...link? Osram, Vishay , Opteck and others have some nice PIN photodiodes good for high frequency IR with plenty of bandwidth for this testing. I almost wish I'd smuggled some of my work home now to be retrofitted into this purpose.

"It occurs to me that one of the things that might be happening with the violet marker that Geoff was talking about is that rather than acting as an absorber it may be functioning as a coating to improve the impedance match between the CD edge and space which would help get energy out of the disk itself. "

Hmm. Seems a reasonable hypothesis.

"Most of this stuff seem rather measurable if any of us cared enough to go to the effort. But it's more fun and a lot easier to simply curl up with the laptop and speculate. And make bad puns. What we need is a troupe of technicians to look into this under our august guidance."

Well my son is almost ten now. Maybe it's time for his first lab coat. He did master the art of doing dishes fairly well. ;-)
RE: Speaking of carbon black. Has anybody tried some Sharpie?, posted on August 30, 2009 at 14:03:31
rick_m
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 I'm all for child labor. Spare the job and spoil the child...

Looks like the CD laser is 780nm so we'd need a source of that wavelength. It's not clear to me if DVD drives actually read CD's at a different frequency. A lot of people make surface sensors, just took a quick scan and haven't found one quite right yet.

Rick

RE: Speaking of carbon black. Has anybody tried some Sharpie?, posted on August 30, 2009 at 12:20:11
geoffkait
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 You guys are making it way too complicated. Take a red sharpie and a piece of pure medium blue-green (turquoise) paper. Write your name on the paper with the red shapie. What do you get? Recall that the CD laser is in near IR, i.e., almost red, and the DVD player laser is red. This is not rocket science, fellers. Never up, never in.

RE: Speaking of carbon black. Has anybody tried some Sharpie?, posted on August 30, 2009 at 14:12:24
rick_m
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 Since I don't know off the top of my head the likely characteristics of pens, dyes and paper, assumptions are too risky and could easily lead to faulty conclusions.

The less you know, the more careful you have to be and I know little enough in this area that I need to tread gently. But you are probably right, at least it seems reasonable...

Rick
RE: Speaking of carbon black. Has anybody tried some Sharpie?, posted on August 30, 2009 at 15:51:40
geoffkait
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 Codename Turquoise (from MD) applied to both circular areas of the top of the CD tray, proves the following:

1. Scattered laser light is a much bigger problem in CD, DVD and SACD players than anyone ever suspected.

2. The scattered light is sufficiently powerful to be detected by the photodetector.

3. The photodetector doesn't know the difference between real signal and scattered light.

4. The Reed Solomon error correction codes do not take care of the scattered light problem.

5. The CD player's black plastic tray is very ineffective for absorbing scattered laser light.

6. The analog output signal can be improved by a very large percentage by improving the optical performance just a little bit.

interesting, posted on September 5, 2009 at 13:11:20
unclestu52
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 The issue of scattered light was addressed at the dawn of CD tweaks. In fact there was a Sanyo, IIRC, player which had their drawers dyed green. On addition there were reports of tweakers spray painting their drawers with a mat green paint to achieve the same effect. Philips offered a player which had a green light shining on the playing dis. and In fact Simply Physics offered a kit to install this light in any Philips mechanism, IIRC.

The CD Greenback (Stereophile recommended list in Feb, 1992) also addressed the same issue. the painting of the edges of CD's all address the issue of scattered light, but supply work at different sites.

I suspect the limiting orifices once marketed earned some of their benefits by reducing the amount of off centered light reaching the laser lens.

In the last item it is interesting to note that their additional weight on the laser lens assembly was responsible for a slowing of the error correction circuit. Back in 94 or thereabouts, I experimented with adding ferrofluid to the motor coils in the laser assembly. It did two things, it dampened the motion and it also increased the motor strength, speeding up the error correction portion of the focus circuit.

The result was a clearly more dynamic sound and with increased detail. It was quite dramatic in my machines. Note there is a an issue of being careful about the amount of ferrofluid used. Too much and it can splash out and contaminate the laser lens. There is no way you can clean it off without destroying it. The second is you need to apply equal amounts to each of the motor coils or the circuit will not work properly. I notified the company I purchased the fluid from about this and for a while, Ferrofluidics lasted this application as a is for their products.


Stu

Yes, that is interesting, posted on September 5, 2009 at 15:52:50
geoffkait
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 What is also interesting is that green is not really the best color for the application, which IMO is actually blue-green. There are a number of green mats, including Marigo's, that have been around a long time, as I'm sure you know. There is some Italian player that employs the blue green color around the transport area, similar to Codename Turquoise, you know, from MD. Codename Turquoise is quite capable of doubling (yes, I said doubling) the player's performance; it makes all the green thinggies seem like child's play by comparison.

Also interesting is just how far one can go using a number of colors on the CD, a rainbow of colors you could say, not only around the outer and inner edge but in the area just outside of the spindle hole where there's no data.

easily explainable, posted on September 10, 2009 at 10:57:14
unclestu52
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 by considering the CD disc itself acts as a light waveguide of sorts and the interface between the the plastic and the atmosphere can readily become a reflective interface even if reduced in intensity. Then s-considering the reflective metallic layer is applied so thin you can see through in many cases, even the back surface of a clear CD will act similarly.

No rocket science here.

Stu

What was the question?, posted on September 10, 2009 at 13:10:29
geoffkait
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 I am not talking about the label side of the CD. I'm still talking about the data side.

You wrote, posted on September 10, 2009 at 21:09:42
unclestu52
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 that the area within the CD outside the playing data zone but outside of the spindle hole affected performance. Notice that I said even the label side made a difference, the inference would be that the playing side was also important.

Stu

RE: You wrote, posted on September 11, 2009 at 02:52:29
geoffkait
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 Stu - I had pointed out earlier that the label side was important due to the color of the inks. What I was referring to in the post you responded to was that markers of different colors - used simultaneously - in the blank are around the spindle hole (on the data side of the CD) can be revealing. This is uncharted territory.

Geoff

Stereophile, posted on September 12, 2009 at 13:20:06
unclestu52
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 in reviewing the green pen tweak reported that coloring the spindle hole also made a difference.

Stu

RE: Stereophile, posted on September 12, 2009 at 16:08:33
geoffkait
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 Don't think we're quite on the same page yet. I'm referring to the use of many colors around the spindle hole, but not the plastic portion. I'm referring to the shiny metal area where there's no data. If it would help I'll draw you a picture.

RE: Stereophile, posted on September 13, 2009 at 14:56:16
unclestu52
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 Some CD's have a circular depression just outside the spindle hole before the silvered section. Coloring in that depression has a similar effect to coloring in the spindle hole itself. That was reported in some magazine article I have long since forgotten.

Similarly the silvered layer acts a mirrored backing which the function of the flashing but since tha laser light is obviously scattered by the pits engraved it is no surprise that the laser light is then reflected along the entire disc on both sides: the bottom because of the obvious reflections and scattering against the air-plastic interface and even the top since some of this reflected light will penetrate the silvered section. Hold up most silvered CD's to a light: chances are you can see through the disc. The gold plated ones make excellent sunglasses and indeed the NASA astronauts used a gold flash on their space suit visors in order to reflect the harmful UV and IR radiation from the sun.

Any coloration due the principles of optics will absorb certain bandwidths of radiation being emitted from the laser. It ain't rocket science here.


Stu

RE: "Any coloration due the principles of optics will absorb certain bandwidths of laser radiation", posted on September 14, 2009 at 04:54:50
geoffkait
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 "Any coloration due the principles of optics will absorb certain bandwidths of radiation being emitted from the laser. It ain't rocket science here."

Oh, really?

According to optics theory, the only bandwidth we need be concerned about for a CD player is the relatively narrow bandwidth of the laser (near infrared) and the relatively narrow bandwidth of the photodetector (also near infrared). According to optics theory only a narrow band of color can absorb light in that spectrum. So it doesn't make sense - if one subscribes to optics theory - that multiple colors of markers (used simultaneously) can improve the sound. Nor does it make sense - from an optics theory point of view - that using the color VIOLET on the outer edge of the CD can improve the sound!

In the case of Mercury Living Presence CDs (which all have a distinctive black and white label) the color RED is the preferred color for the CD outer edge. The colors green or blue green have a deleterious effect on the sound for Mercury Living Presence CDs! So there's obviously more going on here than the overly simplistic story that Stereophile reported on the green pen phenomenon.

While a laser, posted on September 18, 2009 at 12:19:32
unclestu52
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 is technically monochromatic, ever consider what happens to its wavelength as it enters the plastic substrate of a CD/DVD? I certain that it changes, however subtly: similarly the wavelength must also alter slightly as it penetrates the mirrored backing, that coupled with the diffraction of the informational pits which also scatters light also has some effect, particularly as the light is being reflected between the silvered sections and the air/plastic interface promoting even longer wavelengths due to the optical properties of the plastic (remembering that the speed of light is constant only in a vacuum)

Incidentally, when you say red is the preferred color for Mercury CD's, I am assuming that that is YOUR preference. Indeed one of the issues of assessing any tweak is that when you post a subjective preference, and do not elaborate on the actual audible manifestations that is being produced ( I am not quibbling that an effect can be heard, merely the nature of the effect heard), you are not pushing forward the envelope for assessment. The decision you seem to prefer becomes more subjective than objective, and there is nothing one can to do to contradict or refute or even support your position.

Stu

RE: While a laser, posted on September 18, 2009 at 14:03:03
rick_m
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 Interesting point.

Light slows down with the index of refraction which for polycarbonate is about 1.58 at 660nm. So the wavelength will be about 63% of that in air. I suppose (I'm pitiful with optics) that this means that the 'color' of a material best suited for absorbing the energy at the polycarb/material interface would be different than the 'color' of a material best suited for absorbing it at the air/material interface. I'm putting color in single quotes because I think that a better term would be uncolor as in the colors that it doesn't reflect.

Supposing even more I bet what you want for coating the CD edge is something that strongly absorbs the laser color (780nm?) while also forming a conjugate match to the polycarb at that frequency to form an effective termination.

Eyeballing the graph in my trusty? 'handbook of plastic optics' it appears that about 10% of the incident energy is reflected at the air/polycarbonate interfaces.

I know Geoff is an optics guy so when he quits rolling on the floor holding his stomach he can show me the error of my ways.

Radio Rick

In addition, posted on September 20, 2009 at 14:49:26
unclestu52
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 a little research into semi conductor diode type lasers reveals that the emission spectra is not truly monochromatic. There are numerous spikes on either side of the principle wavelength, the peaks conforming to a Gaussian curve. For an infrared laser, like thse used in CD layers, the spectra is 3.9 angstroms apart. and while the energy levels drop quite rapidly as you move away from the center wavelength, the fact that exist is of interest. All these combined with the refractive index of the plastics used mean that there is a bit of frequencies involved. The figure often given is the spurious radiation is +/- 5 to 10 nM of the design center.

Since the plastic interface acts as a light waveguide to a great extent, the path way will vary greatly depending where the laser reader is aimed at the disc. reading from the inside out, obviously the inner side will conform more closely to the working wavelength and the the outer edge will probably benefit from working at the longer wavelengths, although all bets are off as the laser is continuously moving from the inner diameter to the outer diameter and more so if the disc is filled to capacity. But it would explain why sometimes different colors have varying effect.


Stu

Not to mention..., posted on September 23, 2009 at 14:35:16
Ugly
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 Semiconductor unfiltered photodiode response is not a single frequency either. Filters aren't perfect either.

It's an analog world and digital is just some abstract dream someone had that can never be realized completely.

Check out the spectral response of the pin photodiode in the link below.

PS I have no idea if this photodiode is representative of the detector found in a CD player. It's just an illustrative example I dug up.

RE: While a laser, posted on September 18, 2009 at 14:40:58
geoffkait
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 You don't need a physics book or an optics book. See if you can guess the only thing you need.

A crayon?, posted on September 18, 2009 at 14:58:23
rick_m
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 That should make the CD wax musical if not poetic.

Or maybe, let's see... not optics book, not physics book, how about a match book? Yes sir, carbon black, that's the ticket.

I actually investigated buying some stick on paper that's supposed to help but it was far too expensive for my meager budget. I bet I could con the kid next door to palm some construction paper and rubber cement from his school (hey, I pay taxes!) and try that.

Yours for sounder sound, R.

RE: Red is preferred for Mercury's, posted on September 18, 2009 at 13:33:47
geoffkait
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 It doesn't matter what happens to the laser light when it diffracts, scatters, etc. through the CD and inside the player in terms of the wavelength changing AS LONG AS the diffracted and scattered light is not detectable by the photodetector as the Primary Signal. For example, if the wavelength of some scattered laser light is 550 nm it should not be detected by the (near infrared) photodetector. Or, if the power of the scattered light is less than some threshold - say 70% of full value (Primary Signal) - it should not be detected by the photodetector. But what is obviously happening is that a lot of the scattered laser light is both of the "detectable wavelength" and the "detectable power level." That's the problem.

Re: Mercury CDs -- I am saying RED on outer edge of all Mercury CDs will be (almost) everyone's preference - it is simply *better* than a CD with no marking and *better* than a CD green marking, which is actually worse than one with no marking. I am saying *better* for anyone who knows what they are listening to. Like everything else in audio, there will always be someone somewhere who will say he doesn't agree about the color RED. I just throw out the outliers. Make life simpler. Heh Heh

RE: I just throw out the outliers., posted on September 18, 2009 at 14:15:57
rick_m
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 Is that a polite way of saying that you ignore anyone who doesn't agree with you?

If so, I'm all for it! Why should I pay attention to people who don't even know as much as I do?

Rick

RE: I just throw out the outliers., posted on September 18, 2009 at 14:56:29
geoffkait
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 Let's not throw anyone out yet since noone is actually disagreeing with my statement that red is the correct color for mercury cds. You don't actually think anyone has ever tried the color red on a Mercury CD other than me, do you?

I find the color, posted on September 20, 2009 at 14:52:45
unclestu52
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 has more to do with the type of laser assembly rather than the disc used. I make absorbant discs of both green and red, and both are interchangeable so it is a relatively easy assesment for me.

Stu

RE: "I make discs of both green and red, and both are interchangeable so it is a relatively easy assessment.", posted on September 20, 2009 at 17:11:37
geoffkait
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 So, what is your assessment?

incidentally, posted on September 20, 2009 at 14:54:53
unclestu52
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 The Dennis Drake produced Mercury Living Preence CDs are in correct polarity and those after he leaves the reissues are inverted. You are aware of this, right?

Makes a huge difference in any assesment of sound.

Stu

I did not know that, posted on September 20, 2009 at 17:18:55
geoffkait
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....

RE: I just throw out the outliers., posted on September 18, 2009 at 15:21:25
rick_m
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 I might try it. I've got a whole clutch of those Mercury CD's that I bought a long while ago and a year or so ago I was seriously considering selling them for maybe 50c ea because they sounded so bad. Then a miracle occurred. Well, maybe not as miraculous as seeing the image of the virgin Mary in the hoarfrost on the window, but still and all it surprised me.

I happened to play one in the newish DVD burner I'd bought for my computer to replace the one that died and son-of-a-gun, it sounded good. About the same time I happened to hook up my upstairs DVD player to my DAC. I've had 'em both forever, but just never got around to it. Lo and behold they sound good on that too. So I've got two drives on my computer and two transports in my stereo that have the same characteristic: I can move disks from one to the other and one will almost always sound better than the other. So far I think I've found one disk that sounds the same between them. So... something's going on that commingles some aspect of the disks and some aspect of the player and affects the sound.

I think it has to do with how the disks are pressed because there's come consistency. For example all the Mercury disks sound the best on the same drive.

I'm pretty sure that I ended up with two copies of one of the Mercury disks so if they sound the same I could use them to assess the effect of redding the rim. But being a moderate, maybe I'd prefer greening it.

You know, it's fun to josh about this, but the sonic differences really aren't a joke. Whatever the heck is going on should be controlled between the pressing people and the player people, the consumer shouldn't be caught in the middle. I'm just pleased that I discovered that those disks could sound good before I got rid of them because there's some music there that I am fond of.

R.

RE: Speaking of carbon black. Has anybody tried some Sharpie?, posted on August 30, 2009 at 20:50:40
rick_m
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 Gee... that all seems logical. Is that really you?

On item 4 ECC... I'd like some clarification. Are you saying that the data ends up the same in both cases and that the improvement is in jitter or back noise on the power supply or some other secondary effect. Or are you actually seeing correlated changes in c1 or c2 errors?

My presumption is that, that, well heck, I don't know.

Enlighten me oh illuminated (sans reflections) one.

R

RE: Speaking of carbon black. Has anybody tried some Sharpie?, posted on August 31, 2009 at 03:16:10
geoffkait
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 ECC was designed to correct predictable, non-bursty errors like scratches or defects. Noone ever considered background scattered light. They still don't.

RE: Speaking of carbon black. Has anybody tried some Sharpie?, posted on August 31, 2009 at 08:30:22
rick_m
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 No, I don't think they did. Or if they did apparently decided that it wouldn't be significant and was really an implementation issue, which you have shown it to be.

Do the drives in computers also respond to treatment?

I doubt that the differences I hear between drives and players are due to overt errors and from what I read on AA people that do a lot of ripping don't see very many disks that really are hard to read. This just seems to be one more proof that in the audio chain there's almost nothing that you can safely ignore.

Pits is pits.... Rick

Cpmputer drives, posted on September 5, 2009 at 13:15:03
unclestu52
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 respond to all CD tweaks. I know I have modified my computer drives using standard CD tweaks with very good results

Stu

RE: Cpmputer drives, posted on September 5, 2009 at 15:42:56
rick_m
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 I presume that you're using digital extraction. I am, but none the less most CD's sound better on one drive or the other playing in real time. Since we've been batting this around I've looked at my drawers and they are both heavily textured black plastic and similar so don't know if that's a factor or not. I tend to find it a feature rather than a problem but I still wonder why. It would be fun to discover what affects it...

Thanks for the input.

Rick

RE: Computer drives, posted on September 10, 2009 at 11:08:34
unclestu52
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 Unfortunately even the textured black surface is reflective, in that the molded plastic is quite shiny for the most part. Way back when, experimenting with paint ( lacquers will dissolve your typical tray !), I noticed that a gloss finish did not work as well as a mat or dull finish, probably because of the reflective properties. Hence I notice the CD mats with a dull matted surface seem to create better performance. While many have simply opted to place a mat or colored surface on the bottom of the CD tray don't forget that even a small piece of mat plastic or paper cut to suit the laser head also has immediate ramifications on the performance.

And yes, different drive mechanisms do sound different. I suspect a lot has to do with the error correction capability. Speaking of which I had an interesting experience doing a repair on an older Arcam machine. It used a CDM-12 transport ( VAM 1202) which wouldn't spin up so I elected to supply replace the entire drive. I noticed that the original was a Chinese made transport and the replacement happened to be made in Japan. The c transport assemblies are aligned at the the factory so it is a simple matter of dropping in the new part. The Japanese transport was significantly better: more bass, better definition and more dynamic. I couldn't be sure since it arrived broken, and I had only a dim memory of how it sounded new, but the owner was ecstatic, and came back asking if I had modified the unit in any way.

Stu

RE: Speaking of carbon black. Has anybody tried some Sharpie?, posted on August 31, 2009 at 20:15:55
Ugly
Audiophile

Posts: 1421
Location: Des Moines, WA
Joined: August 22, 2006
 "I doubt that the differences I hear between drives and players are due to overt errors and from what I read on AA people that do a lot of ripping don't see very many disks that really are hard to read."

When I ripped my CD collection to hdd I was very surprised how many errors could not be ripped through at a real time clip. I used a program (EAC) which through settings could be directed to keep attempting to read a problem zone until the result is error free. Some of my disks took hours to rip error free, some could not be ripped error free at all, some ripped in faster than real time. I could not always see why one went faster than another. Sometimes the flaws were obvious. It would be interesting to go back through some of the disks which produced errors to see if pen markings on the disk or drive could improve my success rate.

Bottom line is now I don't even have to think about my optics, something that has haunted me since optical drives started showing up in my system.

I don't know that the errors are something that is regularly hugely noticeable but I feel better knowing they are not there. My ripped collection sounds great and is really quite convenient. Now there is more time to concentrate on other potential problems such as electrical or timing issues.
RE: Speaking of carbon black. Has anybody tried some Sharpie?, posted on August 31, 2009 at 14:37:52
geoffkait
Manufacturer

Posts: 3515
Location: northern Virginia
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 Any DVD, CD or SACD system will exhibit the scattered light problem. Same goes for HD-DVD and Blu Ray systems, which require a different color absorber. You won't be aware of overt errors because there is no prohibition against the photodetector detecting stray light. But once you hear what is happening you can draw your own conclusions.

I concluded…, posted on September 2, 2009 at 20:28:56
Wellfed
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Posts: 11220
Joined: January 11, 2008



Ooh la la!
light i, posted on August 21, 2009 at 11:20:07
unclestu52
Dealer

Posts: 6982
Location: Hawaii
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 is a weird thing.

Combine all the colors in a rainbow, pigment wise and what do you get?: a kinda blackish mixture.
Combine all the colors of the rainbow, light wise, and you get white light. In optics, black is absence of all light, quite contrary to pigmentation.

Similarly combining red and green paint yields brown. Combine red and green light and you get yellow not brown.


Stu

RE: light i, posted on August 22, 2009 at 02:18:55
Ugly
Audiophile

Posts: 1421
Location: Des Moines, WA
Joined: August 22, 2006
 It knows what its got to do and won't even listen to reason on the subject.

Kind of reminds me of that White Stripes song "Instinct Blues". The whole song Jack sings about how all the animals and plants all know what to do and at the end finally laments "so why don't you".

I did say kinda. I thought it was funny when I first heard it.

RE: Colors, posted on August 15, 2009 at 05:15:23
May Belt
Manufacturer

Posts: 411
Location: Leeds UK
Joined: March 16, 2005
>>> "In my thinking, an understanding, even a theoretical one, helps the promotion of new ideas and products, and application also. This certainly creates a concrete advancement of the art and technology of audio. It leads to replicable results and sets off thinking for potentially other application." <<<

Yes, of course !! In my way, I was trying to say that. I.e that an understanding helps the promotion of new ideas and new applications. But I was ALSO trying to ADD that if one stays solely on ONE understanding (even on ONE theoretical one), one can get 'locked' into that ONE and, if nothing (no other experiences) 'rocks that understanding' then that is where it stays - 'locked'..

Taking the subject of colours. Yes, "colors play different roles in different application", but when you have played with different colours in those "different applications", many of those applications not in any way associated with the audio equipment or the audio wiring or the AC power, one ends up with a dozen different explanations, for the dozen different applications, for IDENTICAL improvements in the sound !!!!!!!!!!! But, taking each in isolation, each theoretical explanation appears to be THE one.

Taking the subject of chemicals. The same applies. Apply some chemicals to certain things and the theoretical explanation of 'it is dealing with static' will hold up !!.

But, if you apply a particular chemical to (say) 'deal with a static problem' and it DOES 'deal with the problem of static', then the theoretical explanation appears to be THE one. But, if that particular chemical just happens to be a known 'stress' chemical in Nature, then the resulting sound will be WORSE !! Even though the problem of 'static' has been dealt with. It is when faced with such things that, on the face of it, appears to be an ideal 'theoretical' explanation, but will no longer explain what has just happened to the sound !!!

>>> "We see colors simply because the wavelength of light associated with that color means that that color bandwidth is being absorbed by the product colored that way, and the other wavelengths reflected.

Thus a blue object, which corresponds roughly to 420 nM means that other wavelengths are being reflected." <<<

Either I am misreading you but I have always understood it was the other way round.
That it is ALL the OTHER colours (other wavelengths) being absorbed by the object and the one colour one sees is the colour (wavelength) being reflected (rejected) - i.e NOT absorbed !!

Regards,
May Belt.

RE: Magnetics, posted on August 10, 2009 at 17:22:02
rick_m
Audiophile

Posts: 2538
Location: Oregon
Joined: August 11, 2005
 Hi Stu,

When you say "neglected factor in audio design", you may be right. But probably not as much as in the past because nowadays with high speed mixed-signal designs, switchers, CE requirements and on-board RF systems the system designers at the PCB level have become significantly more sophisticated than they used to be. Everyone now thinks about such things more than they did. Frequently more than they want to. Maybe not enough, but more...

I hate stuff hanging on cables, but it seems to be the order of the day. Buy a new little camera and plug in the download cable and there's a awkward Z-bead just an inch from where the infinitesimal connector plugs into the camera that weighs as much as the camera.

So you ask yourself why isn't this stuff internal since the solution sucks. The answers are usually weight, size, performance and time to market. The latter is easy to explain, if you fail at the last minute it's a lot faster to add a bead to the cable than redesign the product. The weight/size issues are simple, even if an internal solution is somewhat lighter, it's still something that you are hefting all the time even though the interference problem only happens when it's plugged in. For incoming crud you want the impedance to occur on the outside of the case and the bypass filtering to occur at the boundary, again the bead is good functionally. So... IMHO, especially since you rarely carry them around, beads (or sleeves) on speaker wires and such make a lot of sense and adding them aftermarket is easy because the node is accessible. I suppose that the Z-sleeves are similar to clamp on ferrite z-beads in effect. They may not be as lossy, but should produce a discrete glob of impedance to common mode HF signals.

So back to PCB's. There are all sorts of techniques used to handle various signals on boards. While nothing is perfect, controlling crosstalk, impedance and fringing in general is commonplace. It usually hits the fan at converters because the analog and digital signals come together in a small space. In fact it's such a serious concern that in general the converter manufacturer has essentially defined what the PCB has to look like near the device because it's impossible to really characterize otherwise. Their advice to the user is "follow our reference layout [OR YOU WILL BE SORRY]. The latter is usually only implied. Strongly implied. The same thing applies to integrated switchers but even more so. The blasted currents in the surrounding board are so high and fast that have to be VERY thoughtful if you have to do something differently than they did.

Choke-wise, there's a huge range of SMT chokes including common mode ones that can be applied to PCB traces just as they can to wires. There are very good capacitors and some even forming a two-dimensional feedthroughs to help with the bypassing.

Maybe some audio designers are still lagging, but the technology and knowledge to make it all happen are in place and available to the astute designer. One saving grace about home audio is that it's relatively large, or at least can be and that gives audio guys more freedom than those designing portable stuff. It can be a mixed blessing but is usually a good thing.

Regards, Rick

Check your email, posted on August 11, 2009 at 01:17:48
unclestu52
Dealer

Posts: 6982
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 I sent you a private email about some experimentation which I consider crucial in what I mean but you will have to do some experimentation in order to actually experience, it. It was a revelation for me.

25 years ago when I was being trained for a main frame Cad Cam system as a system manger I remember receiving literature on a program which mapped the magnetic field effects on printed circuit boards and its relative effects on adjacent circuit traces. It was quite interesting but costing $100K at the time naturally there was no way we were going to purchase that kind of software.

Still working on the cad cam mechanical programming I was quite interested in examining the shapes of curves generated by various orders of fairing used. I suspect this fairing curves are similar to those used by digital chip manufacturers in generating the analog curves from the digital points presented.

However, I digress. Where I believe we still have a lot to learn is the effects of magnetic interference with adjacent circuits and dielectrics. We know there is an effect but we do not know the degree to which that interference will generate audible artifacts.

Particularly in the current crop of digital products, I notice that the increasing amount SMD devices means that the traces are jammed ever closer together, in smaller and small chassis. I wonder if that is really a benefit sometimes. You example of the the circuit breakers and switchers. High current draw devices may be generate significantly more EMF fields, which are often neglected in many designs, particularly since many audio manufacturers do not : 1) have the necessary expertise ( sometimes) and, 2), have the software to to a proper analysis. I find many designers, well respected ones , too, who depend a curious mix of trial and error in the arrangement and placement of the components on a PCB. But the situation is exacerbated by the limited knowledge of such factors. This may be well known in the instrumentation world, but not so in the audio world.

Take the Daletech website, for example where they manufacturer a low leakage power cable. Prior to discovering their website. I had never stopped to consider current leakage as a factor on cabling, particularly power cables. There is much to learn from yet and much yet to apply.

Stu

RE: Check your email, posted on August 11, 2009 at 02:20:20
Ugly
Audiophile

Posts: 1421
Location: Des Moines, WA
Joined: August 22, 2006
 "We know there is an effect but we do not know the degree to which that interference will generate audible artifacts."

I disagree with the notion that accurate enough models can't be generated. I would suggest that the real problem is that accurate models which guarantee the resolution you are talking about are just to unwieldy for a computer, audio designers can lay hands on (maybe anyone can lay hands on), to give answers fast enough to be useful to design with.

It would take too much processing power to simulate entire audio systems at an accuracy level that covers everything audible in the least immune part of the system. On the contrary if one sets the accuracy resolution just high enough to only cover what is audible for the most immune part of the system then important details of interactions occuring at less immune circuit sections get overlooked.

If I tried to predict the first paths around this problem which we may see show up: we can use our intelligence to make decissions about where the computer needs to spend most of its time. In some areas of circuitry relatively high levels of aggressor noise energy may be completely inaudible, but in others audible noise will result from low energy level interference fields. If we can somehow instruct the computer to only simulate to the necessary level of audibility according to each circuit sections immunity/susceptibility we could potentially save alot of compute time. The problem is it's still a big job to just try and make these decisions accurately.

Then again, maybe someday there will be fast and affordable computers with the horsepower to brute force through the problem at the level of detail necessary for the most susceptible sections of circuitry.

It's a rock and a hard place which should work itself out in time as computers get really really fast and powerful. We just aren't there on a practical level...yet.

Of course, it is just an opinion I hold.

RE: Check your email, posted on August 11, 2009 at 08:46:19
rick_m
Audiophile

Posts: 2538
Location: Oregon
Joined: August 11, 2005
 Hmmm,

Have you actually experienced this limitation due to compute power? It just doesn't seem likely from my experience with FEA on weak computers. And, as you well know, you can divide and conquer almost anything.

Speaking of FEA, you can probably do a fair amount of this sort of thing using FEMM. It's free and better than the stuff that cost $10K a few years ago. I've been very impressed with it and it's easy to control the mesh density in various areas to get high resolution where things are interesting without wasting compute power out towards the boundaries. It will do 2D and axisymmetric problems but that's rarely much of a limitation. In linear systems you can use orthogonal slices and add the vectors at points of interest if you've got something really grully.

And it makes pretty pictures. The link below will give you an idea.

If you haven't already done so, try it. It's really fun. A word of advice, you've got to read the instructions as the UI is, er, unique. But it actually makes sense, works well, and is easy to learn but almost impossible to intuit. I tried to get Stu interested in it but I don't think he's anted.

Rick

It ain't the modeling, posted on August 11, 2009 at 12:18:48
unclestu52
Dealer

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 that's an issue: it's the isolation of the inductive qualities. Implementation for a solution is the key as I see it. However, how do you isolate individual pathways from EMI, particularly on a dense PCB?

Traditionally distance has been the solution but that is not quite practical.


Stu

RE: It ain't the modeling, posted on August 11, 2009 at 13:16:30
rick_m
Audiophile

Posts: 2538
Location: Oregon
Joined: August 11, 2005
 "However, how do you isolate individual pathways from EMI, particularly on a dense PCB?"

Put them on another layer that has a plane in between. Use differential signaling if available. Make sure that there aren't common impedances. Control the risetimes of the sources and filter at the sink. Use a constant Z line with buildouts and terminations. Use guard-rings for leakage and to pick up the fringing. Put little metal boxes over bad sources and sensitive spots. Use energy absorbing stick-ons to reduce fringing from IC's. ...

One of the most important things is to do a thoughtful layout in the first place, it takes a load off the router and gives a superior result.

Not really a dramatic change from building stuff with tubes and point-point wiring. In some ways it's better as PCB tracks are a lot more determinant than wiring harnesses. Being small isn't all bad, the lines may be closer together but they aren't as long either. I guess the summary is that versions of the old techniques are still available and a bunch of new ones too.

What IS bad is that when all is said and done the parts are so small that you can't see the wretched things if you have achieved a reasonable maturity...

Rick

I've thought of that, posted on August 12, 2009 at 12:27:41
unclestu52
Dealer

Posts: 6982
Location: Hawaii
Joined: March 5, 2005
 About a decade ago I got a chance to examine the internals of a Mare phono preamp, solid state design and highly rated by the Absolute sound. Not exactly a break through design but what made it interesting is that it contained very little wire, using just the leads of the various components as the points of connection, and basically it was formed into a three dimensional layout. A true point to point layout, you could say.

I have seem triple layer boards used in some very high end digital gear too. However the claim that PS Audio made way back in the 80's sort of haunts me. They claim that a good sounding speaker cable consisted simply of two leads placed 10 inches apart. It is fascinating to see the modelling used by such people like Analysis plus who claim their concentric ovals make for a better layout.

One can use the inductance's generated to further propagate signal or more properly to enhance it, but it is very difficult to eliminate its effects on adjacent circuits.

About twenty years ago. I was experimenting with placing mu metal shields over critical IC's in digital gear and then covering all of them with copper tape and then grounding them. Eventually I expanded to doing the same to every semiconductor with some startling improvements in digital sound. In this experimental stage of working with mum metals, it was fascinating in that it revealed the magnetic inductance's certainly do affect sound but in many cases one can not avoid these influences.

Turntable motors are one example. One reason why those super turntables generally sound better, I believe, is the simple fact that they locate the motors further away from the cartridge. I have tried wrapping a LP-12 motor with mu metal and heard a noticeable improvement. Similarly placing a large ( 3 inch diameter) ferrite ring above or below the motor similarly seems to shrink the magnetic field generating sonic benefits.

But why stop there. The same ferrite ring located above the magnetic chuck of a CD spin motor similarly improves the sound, and I suspect it also involves the pulsing field generated by the spin motor itself ( yeah I know about belt driven CD players but it seems that they follow the pattern of the larger turntable design).

In short, yes, a three dimensional layout would be far superior, in my opinion, although I envision maybe three or more separate boards in order to achieve true distance between the traces. I wonder when we will see it ever implemented.

Stu

RE: I've thought of that, posted on August 12, 2009 at 13:33:25
rick_m
Audiophile

Posts: 2538
Location: Oregon
Joined: August 11, 2005
 Stu, you're just ahead of your time!

You might enjoy pursing the link below, they make stuff just for the applications of which you speak. Their EZ-foam is especially nice, it compresses enough that you can stick it on most any metal/metal surface for a finger-stock type seal. Check out their SD series which are ferrite sheets for atop IC's.

Probably nowadays most boards, except computer motherboards, are two to eight layers. Four gives you useful power planes, six more routes and eight enough density to fan out most BGA's.

I wouldn't think that 10" spaced leads would remotely be an optimum speaker cable. Too much loop inductance and way too large of a current loop to invite interactions and interference. Just the opposite approach of most of the Kimber products which I believe are a good system design.

There's something to be said for air spaced point to point circuits. The main things are low leakage and capacitance and no dielectric absorption. But they aren't good for fast currents, hard to repair and cause high suicide rates among production workers. Life's just one compromise after another...

Rick

Been playing around, posted on August 12, 2009 at 23:11:16
unclestu52
Dealer

Posts: 6982
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 with those molded ferrite sheet stock from Digikey sized to fit some IC's. Interesting, can't say I really like them on analog output chips. They work alright for pure digital chips and for control chips, however. Sonic improvements can be heard by application of copper tape on the ferrite's, ( I use the 3M 1180,which has conductive glue in order to speed up the propagated inductive current across the ferrite surface).

I fracture the larger ferrites and shape it using a diamond sharpening stone. This seems to work quite well to make odd sized pieces for those unusually shaped IC's located in a typical digital/video player.

I have used the mu metal and other magnetically permeable material in a more unusual manner than standard. I find that use of these materials enables me to "channel" the magnetic fields. That is to move the fields to where I believe they work better and or "faster". I do believe the predominate use is to attempt to erect a "shield" of sorts but I find that very often that usage leads to other issues, like needing extensive amount of material in order to effect a positive change, requiring a massive amount of material to achieve results.

Latest application has been on phono cartridges. Since most work by magnetically induced designs, I have been experimenting with placing an appropriately sized ferrite sheet on the top of the cartridge body, hoping to "pull" the lines of force closer to the coil structures so that the coils "see" a more powerful field. It works by increasing the outputs giving greater dynamics (you have to be careful as it makes the cartridge motor more "powerful" and you may have to increase tracking force slightly). However, I have noted a "slower" presentation" of sound simultaneously. Adding a layer layer of mu metal foil covered with copper speeds things up significantly, again working on speeding up the magnetic propagation speeds.

Again I am working to speed up the flow of the induced magnetic fields, and to attempt to pull them closer to the actual body of the the magnet or to the field which generates the EMF. Magnetism is one force which seems to work better when pulled closer to its source.

At any rate this rather primitive experimentation leads me to believe that physical space is an important aspect to design. I am sure (in examining a few multiple layer boards) that they employ extensive ground planing to electrically isolate adjacent circuits. However I suspect the induction created even in regards to a ground plane may not be a truly optimal design. I believe that in order to optimize certain signal paths, we need to free them from the inductance normally associated with a very dense board.

The Kimber design of braiding their conductors to approximate the 90 degree crossing works well for a relatively inexpensive and closely spaced conductors. But it interesting to note that simply "puffing" up their base line speaker cables often sounds better than their more expensive more rigidly spaced encased designs: probably because of dielectric absorption and lower leakage. I cannot believe that these issues have not been addressed with conventional audio gear, especially those components which are rather astronomical in cost.

It is interesting to note that the once highly rated Jadis gear employs point to point wiring for the most part in their analog circuitry even on their preamps. On a tube design, that is not really difficult to implement (the preamp I examined, JP-80, was a two part component, power supply on one chassis and the analog circuitry on the other: the PS was on a circuit board, the analog was point to point wiring). The unit, very expensive, had quite a remarkable midrange quality, although frequency response was no better than many other units I have heard.

That Mare phono unit I opened up, I didn't get a chance to really assess its sonic qualities. The build quality was extremely intricate: a giant jigsaw puzzle if I ever saw one, but it was a little jewel in many respects, and indeed a nightmare to construct or to repair. The reviews had it as being an extremely fast and detailed unit, and one which did not sound like most solid state units. Interesting to note that it was enclosed in a wooden chassis, thus even lowering any capacitive reactants with the live circuit. Such construction practices are well suited for building in China, BTW, where labor is realtively cheap nd indeed, many Chinese tube units are built in the manner of the Jadis, employing point to point wiring.

Perhaps I harp on the various inductance's more than others because I suspect their detrimental effects are frequency and power related, and thus more non linear. I find the ear can compensate quite well to linear issues:those non linear issues create small but more annoying discontinuities.

Or maybe I'm just pissing in the wind....


Stu
PS, posted on August 12, 2009 at 23:43:24
unclestu52
Dealer

Posts: 6982
Location: Hawaii
Joined: March 5, 2005
 That clear EMI absorber looks interesting for the displays of many digital products, since I notice there is a lot of leakage from them.

Also in terms of the ferrite cores and such. my most recent experimentation has been to impregnate some beeswax with ferrite powder and mold it around certain components. Again interesting results, particularly around standard EI transformers which leave the sides of the coils completely exposed. It very interesting in that the beeswax is not super solid and thus allows the ferrite powder to move slightly and over time the effects become more noticeable as the ferrite re aligns itself. Again it is interesting as most ferrite forms feature a fixed orientation...



Stu

RE: Self orienting ferrite., posted on August 14, 2009 at 12:35:23
rick_m
Audiophile

Posts: 2538
Location: Oregon
Joined: August 11, 2005
 Now that IS interesting. And it makes sense to me, there will be torque on the individual grains to align themselves for minimum energy. Perhaps a good test would be to measure the perm and then apply a DC bias over a heat cycle, measure again and repeat.

You could come up with a component that, like human males, improve with age... (if they don't melt or sag).

Stu, I've got to say that of all the people I know in person or virtually that you investigate the most interesting things!

Rick
I work best, posted on August 15, 2009 at 01:16:46
unclestu52
Dealer

Posts: 6982
Location: Hawaii
Joined: March 5, 2005
 under the light of the full moon....

Oawooooo!.......


Thanks for the compliment.

Stu

But isn't it precisely the modelling which should rell you..., posted on August 11, 2009 at 12:31:40
Ugly
Audiophile

Posts: 1421
Location: Des Moines, WA
Joined: August 22, 2006
 "However, how do you isolate individual pathways from EMI, particularly on a dense PCB?"

IOW the modelling should tell you whether a given location for a set of circuitry is expected to either have audible or inaudible problems caused by it's environment.

Edit: uh... I meant "tell" not "rell" for some reason the titlesaren't editable for me.

RE: Check your email, posted on August 11, 2009 at 12:08:23
Ugly
Audiophile

Posts: 1421
Location: Des Moines, WA
Joined: August 22, 2006
 Howdy Rick. Thanks for the link. I will be playing with this software more now that I have more idle time. I desperately need something like this in my tool box.

BTW I have high hopes this idle time is almost gone for me now, but still to early to celebrate.

"Have you actually experienced this limitation due to compute power?"

I cannot tell a lie. Well, yeah. ;-) Even in SPICE, which is hardly a capable of system level simulation, constraints must be intelligently be set to get done while my attention hasn't wandered off. In an ideal world the simulation would consider everything at the limits of modern theory...quantum level (?). At least in my thinking this holy grail of tools which we seek would not only include the powers of SPICE but the capabilities of the type of software you link but on a 3D level. That is just plain and simply way to much to ask of my dual core AMD and two gigs of RAM as powerful as it may seem.

I was telling Stu below that I can imagine the promised land but haven't seen it. To make it simple enough for designers to really be useful to whatever level of detail is deemed necessary it would take an integration down to the part model libraries level of at least mechanical, electrical, to include all important players in a 3D capacity. The software would have to be tweakable like SPICE (and I'm sure your FEMM type softwares are) in a way so as to make simulation results available quickly. Then you need a jockey with the training and intelligence to use it all effectively.

Ideally when I get my layout artwork done the entire system could be imported with all PCB's, electronics, enclosures, interconnects, mechanical apparatus etc. define stimulus and hit the go button. Hell why not throw ability to simulate due to stimulii of optical, thermal, mechanical, chemical nature, besides just electromagnetic, in there too while I'm writing my wish list to santa clause?

I think your points about dividing and conquering are the only hope for us at first when this level of simulation is expected. This is where all the work comes in and the inherently lazy, or should I say schedule limited, start making shortcuts in my experience. The shortcuts which maybe shouldn't get taken when attempting to get answers at the level Stu seems to be asking for is probably the biggest problem.

Edit: I probably should have said - That is just plain and simply way to much to ask of my dual core AMD and two gigs of RAM as powerful as it may seem, I THINK. I am not a programmer and don't pretend to be. Maybe I am overlooking something one of the real programmers from the seventies who gave us things like, for example, Atari 2600's running on 8K of RAM and cpus running in the thousands of clock cycles per second which had games arguably funner than what youngin programmers come out with on modern boxes utilizing what may comparatively considered to be nearly infinite system resources.

RE: Models, posted on August 11, 2009 at 14:23:09
rick_m
Audiophile

Posts: 2538
Location: Oregon
Joined: August 11, 2005
 Well, you have a very good point. And certainly that's the way design is headed. Maybe it's already arrived for those with access to state-of-the-art tools, I really don't know. Sigh...

Good luck ending your premature retirement!

Rick

RE: Models, posted on August 11, 2009 at 18:12:07
Ugly
Audiophile

Posts: 1421
Location: Des Moines, WA
Joined: August 22, 2006
 Thanks bro!

you make many good points, posted on August 11, 2009 at 04:09:54
unclestu52
Dealer

Posts: 6982
Location: Hawaii
Joined: March 5, 2005
 but consider a 64 pin DAC chip for example. The pin outs are so tiny and so close together surely any interaction between the legs are severely limited by what you can do on such a small scale. Miniaturization has been both a blessing and a curse in this regards. It may have solved some issues by creating a much shorter and therefore faster path way but the EMI interactions still remain.

One of the crucial factors increasing popping up in the audio world and one which has plagued data systems for some time has been the random 1/f noise. it does not dissipate with the miniaturization but if you believe some of it is due to interference from adjacent circuitry then sometimes it seems the problem may be compounded.

I believe with the latest generations of PC we have the power to run such programs. Implementing it is a totally different animal however. I believe the issue is more of the implementation rather than the seeking out of the problem.

Stu

RE: you make many good points, posted on August 11, 2009 at 11:29:36
Ugly
Audiophile

Posts: 1421
Location: Des Moines, WA
Joined: August 22, 2006
 This miniaturization of the circuit dimensions isn't the problem, at least as I see it, accurate models should work on any scale. Obviously miniaturization brings with it more and more system complexity, but this complexity doesn't move the analysis beyond the capability to model it if one has time to consider the complete system in it's added complexity. Same goes for the various noises which are from within electronic devices, such as Schott etc. etc. etc., ie they are fairly well characterized and predictable AFAIK.

I think you hit upon the real issue in your last paragraph. If we do have the processor power the tools which make it easy for a designer to do system level 3D analysis just aren't there. It's a circular argument I have but my suspicions are that if this tool were to exist to make it easy for designers and accurate enough to cover everything at once, then you see the limitation of desktops we can practically attain.

Certainly a difficult thing to back up using a logical argument other than to point at reality and say "show me the money". Where is this easy to use software that doesn't take until next year to simulate that I can import my engineering files for a system containing multiple PCB's stuffed with multiple tiny SMT devices and utilizing high speed digital and high sensitivity analog sections, switching power supplies, enclosures of various materials (grounded?), cables, AC power inputs etc. ad infinitum.

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