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In Reply to: RE: rainbow foil posted by unclestu on June 25, 2010 at 14:05:57
From the Shakti Stone White paper:"Through a unique application of quartz oscillators, a broad spectrum of RFI is attenuated. Being a piezeo-electric (sic) material, quartz is capable of converting an electric field into mechanical energy. In situations where quartz is employed in active components, the desired goal is to accentuate one resonant frequency to the exclusion of all others. However, within this stage of SHAKTI, quartz is used in a manner to produce the broadest sampling of frequencies to better absorb the somewhat unpredictable EMI. One of the reasons quartz has never been used in this type of circuit is because, as effective as it is as a converter of electrical energy, its very high Q means that most of the conversion to mechanical energy swiftly changes back to electrical. To overcome this problem, careful experimentation produced the necessary resistive element that is incorporated to substantially lower the Q. The result is effective dissipation within the first 1/2 cycle. This stage provides absorption/dissipation benefits for both external and self -generated sources of RFI."
[A little odd that the author chose to use the term piezeo-electric as the correct term is piezoelectric.]
It should be pointed out that the Shakti Stone actually operates - according to the white paper and patent - via the converse piezoelectric effect - conversion of electrical energy (RFI/EMI) to mechanical energy. For this to occur successfully - as pointed out in the white paper - a resistive element is required. There is no reason to believe that a "piezoelectric crystal" (by itself) is capable of absorbing RFI/EMI without such a resisitive element and every reason to believe it can't.
I therefore propose there must be some other mechanism in crystals, when used individually or in groups - besides piezoelectric effect - responsible for the change in sound -- at least when discussing RFI/EMI absorption. I also propose that - in almost all cases - the actual operation of a crystal or group of crystals in an audio system has nothing whatsoever to do with RFI/EMI absorption - rather acoustic/mechanical energy absorption!
Edits: 06/26/10Follow Ups:
The damping material can be something as simple as blue tack or any other viscous retaining putty. Again the principle is to simply convert the EMI/RFI absorbed into mechanical motion and thus to heat. You can use a crystal very precariously balanced ( say a round shape) or use a little dab of blue tack as I do. I like irregular tumbled crystals because I believe the frequencies absorbed are broader in bandwidth because of the irregular shape and since the vast majority of EMI/RFI currently encountered are higher in frequency, I use physically smaller crystals. Larger ones I place closer to the power transformers where the fundamental frequency is 50 or 60 hz.
In my experience crystals will absorb EMI/RFI irrespective of the mechanical resistive element. Without the mechanical lossy coupling however, the crystals impart a high frequency edge to the sound. This has been borne out with much experimentation with those beautiful but awful sounding fish scale type granite often encountered in shelving. Also in borne out in experimentation with larger quartz clusters which I collect.
Stu
There is a good chance you are misinterpreting what the crystal is actually doing in the case of the transformer. I suspect that the crystal is actually converting mechanical energy to mechnical energy. I.e., that no EMI/RFI is absorbed. Also that this mechanism of conversion of energy is NOT piezoelectricity but another, different mechanism in the crystal. Recall that piezoelectricity is the conversion of voltage to deformation of the crystal and that the converse piezoelectric effect is the conversion of mechanical pressure to voltage. So it doesn't make sense that EMI/RFI is being converted because voltage is either too low to accomplish much of anything in the crystal or that the pressure produced by EMI/RFI is too low to produce much of anything in the crystal. The actual mechanism is the vibration of the atoms of the crystal produced by mechanical vibration. This characteristic of the crystal - of mechancal/acoustic energy conversion - is more obvious when the crystal is placed on the wall (at points of high mechanical or acoustic energy), on speaker cabinets, on top of a CD player, near electron tubes, or in room corners.It is a *coincidence* that most crystals used in these audio applications happen to be piezoelectric; their primary characteristic is that the symmetry of atoms in the crystal lattice produce the vibration I'm referring to when activated by external sources. Crystals that are not strongly piezoelectric, that are only weakly piezoelectric, can also be used quite effectively in these applications. I now use at least 12 different crystals in my Brilliant Pebbles, depending on size; there are 4 different size of these products, including the X-Large size for very large rooms. Size of crystals in my products varies from 2 mm to 15 mm.
I do not close the door on the proposition that in some case, in some application, crystal could absorb EMI/RFI, but that it wouldnot be piezoelectric effect inthat case either, it would be some internal atomic mechansim - different from the one responsible for absorbing mechanical energy - within the crystal lattice structure that is responsible. But, as I said, almost all audiophile applications of crystals, if not all, appear to address mechanical/acoustic vibration, not EMI/RFI.
Edits: 07/17/10 07/17/10
Interesting post Geoff. I know you've mentioned this before but I appreciate the details. Maybe those jars of agates are doing more than I would have thought. They sit on a half-wall just behind my chair and above my head. I've always thought I should try a diffuser on the wall but it's never seemed cause problems as have other walls in the past. I'm sure being short helps but maybe it's also the rocks...
Is being in a lattice important? I think this would be good excuse for an experiment, I could go collect a bunch of basalt rocks from the beach which are far more common than agates. In fact I've always joked that if the beach were mostly agates that we would collect the black rocks.
Have you measured these effects? I've got an accelerometer around somewhere but I need to build a preamp for it. I could glue it to various rocks and, er, see if they Rock? I know they roll, even a casual observer can see that at the coast.
Rick
The basalt rocks don't have the well organized symmetrical crystal lattice that one finds in clear quariz, smokey quartz, aquamarine, topaz rumbled stones. When I refer to *crystals* I refer to quartz, agate, aquamarine, ruby, topaz, jade, tourmaline, etc. Of course, the purer the crystal the more uniform and symmetrial the lattice structure. This is not to say basalt will do nothing, there could be mass loading going on...who knows?The lattice is important because the atoms in the material are allowed to move back and forth with ease. If the structure were not symmetrical the atoms could not move freely.
Big doesn't necessarily mean better. My Mikro size BP comprise crystals of various types that are only 2-3 mm each. A Mikro packet comprises only 25-30 of these minuscule crystals.
Measurement is best done with SPL meter and test tone. This method allows determination of locations in the room where improvements to the sound will be experienced. Such as in or near room corners. Or on the wall at first reflection points, for example. Of course, anyone is free to measure these things any way they wish.
Edits: 07/17/10
A couple of questions...
1. Doesn't the container, i.e. Jar or Bag make a large difference in how rocks rock?
2. So if one were to set up his SPL meter on it's cute little tripod in the corner, note the SPL vs Frequency of a swept tone and THEN add the jar of pebbles and repeat... what sort of deltas would one expect?
I've come to believe that the details of acoustical specular reflections and general absorption have an outsized impact on our perceptions but I don't how to optimize it except raw trial and error.
On another note, you offer small packages of pebbles intended to be stuffed or propped where wires enter gear. Is that mechanical also?
Rick
I use the spl meter/test tone strictly to determine the points in the room where there are peaks more than 6-8 dB above the average level. These pressure peaks can be anywhere in the room, in the ceiling, on a wall, or anywhere in the 3-D space.The ziplock bags of crystals dissipate energy where the peaks are located. There are a great many peaks in the room, so the question will arise as to which ones should be treated first. :-)
The Mikro is smallest BP (about 1 oz) and can be placed on top of the RCA jacks, and yes, am pretty sure they act mechanically. They can also be placed next to small vacuum tubes, on top of CD player, on power cord plugs, taped to glass windows, sliding glass doors, taped to the wall in stategic locations, etc.
I should also add that my BP undergoes special treatments, even the assembly and choice of crystals is proprietary. All of this, including all of various applications for the different sizes, took a little bit of time to work out, as you can appreciate.
Edits: 07/17/10
"All of this, including all of various applications for the different sizes, took a little bit of time to work out, as you can appreciate."
I do appreciate that, way too many variables in audio. It almost is the very definition of audiophilism.
A few years ago I stuck a piece of RG-58 in my ear (NO, don't go there! It had a BNC connector on it and didn't go all the way through) and tapped on the other end (it was maybe three meters long). Twas right up there with Big Ben albeit monotonic. Rang for seconds. So I hooked it up to a scope and did the same thing and it looked just like it sounded. There's dielectric helping things out. Maybe I should try again with a crystalized version...
By the way it was regular ol' solid dielectric, I suspect foam would be better.
Rick
Somehow I think you are arguing again yourselfs.
"There is no reason to believe that a "piezoelectric crystal" (by itself) is capable of absorbing RFI/EMI without such a resisitive element and every reason to believe it can't."
Nah... Their Q may be high but it's not infinite and the Q is really only high if the crystal is very pure, cut on plane boundaries and mounted at mechanical vibration nodes in a vacuum. BUT, knowing that you are an old communications guy I know that you know this, you know?
"I also propose that - in almost all cases - the actual operation of a crystal or group of crystals in an audio system has nothing whatsoever to do with RFI/EMI absorption - rather acoustic/mechanical energy absorption!"
Well, you may well be right and it should be easy to tell whether the piezoelectric properties matter, just try a jar full of basalt and see if that causes your emotions to erupt or a some sandstone to smooth out the rough edges of the sound.
I know Stu uses constrained damping with crystals and so apparently does the Shakti stone people. It only makes sense, for their application lossiness i.e. low Q (For the jargon impaired Q (the 'quality' factor) is the energy stored over the energy dissipated in a cycle) is desirable for the same reasons that it's undesirable when using a crystal for timing.
No, I don't have little baggies of crystals, pot or dung taped to the outside of my breaker box. Should I? That's an interesting case, what do you suppose is they mostly do, if anything? I bet it depends upon where you stick them. Whether they damp out some of the induced mechanical hum or suck up EMI or just make the user feel better or cause him to be electrocuted they seem to me bound to be a force for good in reducing his listening angst.
Yours for crystalline clarity,
Radio Rick
with no real experience with crystals, just more angst and snootiness from the peanut gallery.
...I was a usin' FT-243 crystals when I was in Jr. High back in the ol' Kennedy era. Now them was the days, not a synthesizer in sight!
Why I even used to use a crystal microphone and in the really old days built crystal sets. And on the face of my watch, oh, nevermind...
R.
His estrogen patch must be running low.
Thanks for the concern, but he's probably right, I may not be totally up to speed on the latest Audiophile applications of crystal. But I have found them of use as an aid to consuming alcoholic beverages while listening. The long stem variety is especially good as I can sort of visually center it and twirl without blocking the direct sound field.
I suppose the next step is to obtain one for the navel. Perhaps ruby for CD's, tourmaline for DVD-A's and of course, a diamond for LP's. I understand that if you don't listen to records very often that you can get by with a sapphire...
Rick
When y'all get some experience with the crystals and the applications we're actually talking about, come back around, Gramps.
Edits: 06/29/10
has posted in the past about a large tourmaline cluster which seems to improve sound when placed on his gear.
Stu
I think you're referring to a cluster of agate he keeps around for decoration, but not on his gear. As I recall he never got around to actually experimenting with the cluster. Are we supposed to be holding our breath?
Hmmm, well it seemed large to me when I found it in the mine tailings...
As you can see I'm even using Stu's toroid tweak and some highly refined acoustical absorbing material. Maxed out she is, maxed out!
And it's scientifical, I tried a piece of basalt largely the same size and shape and the tourmaline ore sounded better, and looked better too. My camera batteries went dead but I can even take pictures of the jars of agates and a comparison shot of the rocks once I recharge them if you care. It might be tough to estimate the sonic qualities of the two rocks from a photo but you'd see the visual improvement right away.
Tweaker Rick
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