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I thought about posting this in Isolation but, it is less traveled, so to speak. I had changed the central hold-down bolts on my mono-blocks to threaded brass rods, brass nuts, everything as non-magnetic as I could get it, and got a not-so-subtle change in sound for the better, as opposed to the stock steel bolts. This caused me to think about what it must "look like" electromagnetically at the center of a toroidal transformer. Would anyone like to postulate what is going on in the center of the transformer, EMI-wise, or does anyone know of any kind of white papers or spectral analysis on the subject, that you might point me to? I e-mailed Plitron, but have not received any response yet. I suspect that some will say nothing is going on, if the transformer is built properly, but experience tells me otherwise. Thanks to all.
Follow Ups:
fascinating thread.
i immediately think of some of the best amps out there (Lamm, Boulder, Vitus) who have either A) potted transformers or B) (in vitus' case) a U-type design whereby the field generated is nonlinear.
not saying i'm an expert, just pointing out that it walks and quacks like a duck. transformers are horrible for sound, and mfgs who do more to address the EM fields and vibrational interactions of trannies generally have good sounding products.
Doesn't any material which conducts electricity ALSO have a magnetic field?
Too much is never enough
pictureguy, Brass and Copper are both conductors of electricity, but to the best of my recollection, I've never seen either of them made into magnets. NOT trying be a smart ass, just saying.
Is this similar to the way they separate non-ferrous metals from other waste materials (paper, food, etc) at recycling centers? I saw something on TV a couple of years ago, a conveyor belt at a recycling center that had had all ferrous materials removed by a magnet. The other metals were being removed by an eddy current that was generated by a magnet assembly of some sort. Sound familiar?
Not saying they HAVE been made into magnets, but rather, they WILL have a magnetic field when they conduct electicity.
Not especially trying to be a SA, either, but it IS called 'ElectroMagnetism' for that very reason.
Too much is never enough
For my 6th grade (might have been 7 or 8th) grade science fair project I made what I called a 'Faraday Induction coil'. I did a number of experiments to illustrate electro-magnetic principles. One such demonstration was of a shaded pole motor....made of an Aluminum pie tin. It would rotate at a fairly slow speed, but rotate it did.
ANY induced current will have a resulting magnetic field. Even in Brass.
I believe the Phenom is called 'Paramagnetic' Aren't some speaker VCs made with Al wire?
Too much is never enough
on how a toroidal transformer works. The magnetic field generated by the coils wound on the toroid forms a donut shaped pattern. The core material of the toroid captures some of that field from the primary windings and uses it for induction on the secondary windings.That being said, there's a lot of that field that escapes outside of the windings. That external field then drops down through the center of the toroid. Any hold down bolt that offers high resistance to that field has the field actually generating work as an induced field is now being generated in that hold down bolt ( Faraday's, and Maxwell's laws).
Brass is significantly more conductive than steel so it offers a faster pathway for that induced field (drained to ground). You can gain even more by using Nylon hardware which is completely non conductive. Incidentally the large steel washer used to compress the toroid does not necessarily have to be changed: it actually will shrink the field some.
I have been advocating this for many years now, and it also works for speaker inductors also. A sense of hardness disappears and there is a greater sense of ease to the music. At various CES I have talked to transformer engineers about this phenomenon, but have been dismissed or ignored by most of them.
Stu
Edits: 04/16/12
I've used 1/4" nylon bolts for the last 10 years, with the transformer sitting on a 1/4" Sorbothane pad. I surmised the nylon bolt would be better inside the 'donut' (than steel) and the Sorbothane pad was to reduce vibration transmission.
I also thought that getting a dished washer made up from 1/16" copper sheet would be an advantage ... but you say in fact the original steel washer would be better (as it would tend to "imprison" the magnetic field)?
Thanks,
Andy
Yes using the large steel compression washer is better at limiting the magnetic field generated. Do line it with copper ( I use 3M copper foil tape, and that counters the electrical field generated by the magnetic field....
Stu
If we are trying to deal with (ie. minimise) two issues:
* the distance the magnetic field of the toroid extends to, and
* the electrical field generated by this magnetic field
... if extent of the magnetic field is no biggie, since:
* it's a toroid anyway, and
* it's shielded off from the PCBs inside the case with a steel divider,
... then, on balance, shirley it's better to minimise the electrical field with a copper retaining washer - particularly when using a nylon bolt?
Regards,
Andy
Good points and I can understand the confusion.
In a toroid, the magnetic field generated runs parallel to the core material, since the windings are radially wound upon the core. It goes round and round, even in the middle, where if you have a magnetic screw, that field gets captured. That, in turn induces a current flow which gain runs 90 degrees to the magnetic field, meaning that the current runs vertically, now.
Remember that the magnetic field is always present in an AC field, and the changing magnetic field also induces an electrical field. Theoretically, I guess, you could go on forever, alternating ferrous and copper sheets.
Thus, a ferrous screw has the property of capturing the magnetic field, but the trouble is that it tends not to release that field and it is strongest at the center where the magnetic lines of force converge. The compression washer is on top of the toroid, and, yes, it does capture the magnetic field, and thus shrinks it, but the hole in the middle does allow that field to drop through to the center of the toroid. I believe the solid screw has the fields from the other side of the toroid sort of "fighting" for the magnetic transfer. Use of a threaded ferrous hollow sleeve may alleviate this issue, but I've never tried it, but it should work theoretically.
Stu
What's the difference between an electrical and magnetic field?
Too much is never enough
I'm not really sure ... someone else brought up this distinction. :-))
But if you think about it, it's (electrical) current which is travelling along the wire which makes up the toroid ... and this current generates the magnetic field around the toroid.
So it looks like, to me, that the magnetic field surrounds the donut of the coil (so a cross-section of the toroid would show two metal cores - 'X' inches apart - with a circle of magnetic field surrounding each core) ... whereas the electrical field surrounds each wire?
Regards,
Andy
I don't know either....but I have my suspects.
I doubt you can have a flow of current without a magnetic field and if a conductor moves in a magnetic field, you will induce a current. The basic motor/generator. Or, to be audio about it, a speaker which generates back EMF.
An electron has a field but I don't know if that is magnetic or electric in nature. I doubt there are motionless electrons above absolute zero.
The physics guys call it 'electro-magnetism'.
Please read the Wiki for the answer to this and other stimulating questions!
Too much is never enough
Seems to me that wouldn't a steel, ferrous containing metal, act like a super highway and actually assist the electromagnetic energy getting to the bottom of the windings of a toroidal transformer, since magnetism likes to travel via iron, path of least resistance and all that, stray/residual energy that it is?
In my previous post I was not using a coppper, flat washer on top or anywhere for that matter, though I had considered it, too costly. The washer supplied with the amp was made of aluminum. I replaced that one with a stainless steel washer and applied a layer of KAPTON (a dielectric) film stuck to the flat side, that faces the transformer. It has been my experience that copper will bounce or reflect back onto its source and that, that can cause bad sounding things to happen when it does. I think some space is needed to keep the reflection from occuring or some way to disrupt the reflection (ERS cloth?) Just a little confusion I needed to clear up, to keep this discussion factual. Thanks for your participation, always appreciated.
A couple of points and questions:
There were a couple of things I was trying to accomplish at once. The brass, while a better conductor of electricity, should also conduct the transformers vibrational forces to the last, and most important third cone in the triad, sitting on the Herbies hushpuckie, supporting the amp. Utilizing a nylon threaded rod would not pass the vibrational energy as well as the brass, but may indeed be a better material to use, electrically although, torque strength could be an issue. The vibrations from the transformer sitting on a 1/4 inch thick rubber pad, that's about all the extra space (height-wise) that I have to play with, would help resolve some of the vibrational issues caused by the transformers operation. Perhaps the gain of absorption by the rubber would offset the loss of transference through a threaded nylon rod.
The 3" stainless steel disc, with Kapton film facing the transformer, should keep some of the escaping currents from reaching and reacting with the other metals and components above and around it, the disc itself included, albeit small parts (nut, etc.) until reaching the aluminum lid of the casework and bouncing around inside thereafter until absorbed by everything else inside, part of a big problem in all casework, I would think.
Is a ground wire necessary if using the brass threaded rod as the transformer is grounded to the IEC inlet and internal to the casework?
Do you know anything about the sendust tape/sheets being offered by Oyaide and available from The Cable Company? The tape is very thin, .1 mm thick (sheets are thicker) and I could "pack-out" the excess space produced when using a 6 mm rod with it or Kapton or Teflon tape and what are your thoughts on wrapping the brass rod (if I use the brass instaed of Nylon) with the various tapes or enclosing it in Kapton tubing?
Sorry, I got wordy. Thanks again.
If the large compression washer is indeed stainless, I would change it to a regular ferrous steel washer with the copper tape on top; using an oversized nylon bolt, if possible. The oversized screw will apply enough compression force to restrict any winding vibration and, of course, the thicker rubber pad will additionally absorb that energy. Remember not all stainless steel is magnetic and here the additional magnetic qualities help restrict the field generated by the toroidal coil windings. Here the ferrous washer will capture the magnetic field and the copper tape will move the induced electrical field.Remember magnetic fields would rather travel through ferrous objects and moves faster that way than even through air. Speeding the field through a flat washer speeds the action of the magnetic fields generated as long as it has a hole in the middle, where the field wants to drop down through the washer in order to complete the field. Again, remember the magnetic field is naturally inclined to complete its loop from north to south poles. It doesn't like it when an unperforated washer tries to keep the field in the plate.
As for your grounding the brass screw, isn't the nut or screw head making direct contact with the metal chassis? If so, it is already grounded to the chassis. If you are really worried, you could add a short wire to the IEC ground.
Insulating the center screw is of no use because it is the magnetic field which is penetrating the screw and no amount of electrical insulation can prevent that. Since that magnetic field is a product of the AC being applied, it is ever present. The two options are to move the electrical field as fast as possible ( using a more conductive material such as brass) or to simply use a screw which is non magnetic and non conductive, eliminating the issue completely. Either option, as you can see, does not require any insulation at all.
Ever examine those shielded transformers? In an EI core, they simply wrap copper tape around the windings to limit the electrical field, although I have some Luxman amps where there is a thin steel box section with copper tape covering the exposed windings. In fact, swapping out the steel screws holding an EI core laminations together with non magnetic screws have similar benefits. A closer examination shows that those screws are 90 degrees to the plane of the laminations for the the transformer and are obviously oriented the wrong way.
Of course, YMMV....
StuPS: I find it beneficial to isolate any transformer vibration to the transformer itself. Passing it to the chassis certainly messes up the circuit, even if solid state, at least in my experience.
Edits: 04/16/12
For those who do not plan on moving their amplifiers - how about doing without the bolt entirely (easily replaced if needed) and using something like a giant HAMMOND choke on top for weight and absorption (?).
I have a few 5H chokes laying about. They weigh ten pounds.
Would this do any good or harm?
You could but I find the EI core types to be detrimental to sound. The issue is that the magnetic field generated by a toroidal transformer is circular. The hole in the middle is necessary for aiding the magnetic field flux. IF you use a VPI Magic Brick, placing two edgewise on either side of the toroid gives significantly better results than one diretly over the middle.
I have in the past purchased large toroids: basically unmagnetized speaker magnet material. These work very well on top of toroidal tranformers I usually augment them by wrapping them with copper tape and generally ground that tape.
Your chokes would work well on the traditional EI transformers, however. Align the choke laminations with the lams on the EI transformer for best results. Well, at least that has been my experience.
Again YMMV.
Stu
I do have a couple of the VPI Magic Bricks that I had placed on top of the casework, over the transformers. Doing what you suggest is certainly worth a listen. Thanks for the suggestion.
Since StillPoints standoffs are so impressive, I wonder what such technology might do to transformers.
My BMC M1 amplifier appears to have no ferrous hold down bolt, but knowing what isolation of these amps does, I wonder what better vibration isolation of the transformer might do. Here is a picture from Stereophile.
Norm,
Judging by the color of the film wrapping the output transformer, looks like Kapton (Polyimide) Film. According to what I have found out, won't have as long a useful life as Teflon, but is a much better dielectric, I've forgotten about the temperature range but, if memory serves, the temperature range is higher. I had researched getting 2 titanium bolts, but there is a $100.00 minimun chargs and two, six inch long bolts, titanium or not is out of line. If I were Trump, I'd do it in a heartbeat though.
I had thought about small rollerball-like assemblies for under the transformers, but that would cause fit problems within the amps, not to mention still longer bolts and more questions about materials usage, because aluminum gets magnetic with current running through it (my understanding) so we are back into currents, fluxes, emi, etc. all over again. Perhaps ceramics instead? Thinking out loud. Regards.
A thicker rubber pad would work very well. If your chassis is a steel one, the magnetic field of the transformer will couple with the chassis. The field will decrease by the square of the distance, so simple spacing will lower that coupling quite a bit. Try at least a 1/4 inch thick rubber pad.Stu
PS. Magnetic fields would rather travel trough anything ferrous rather than air, hence the large steel washer may prove helpful in shrinking the magnetic field generated by a toroid. It is helpful to counter the induced electrical field by simply applying copper foil or tape across the washer. Remember the issue you are working with is the induced currents in the magnetic substances...
Edits: 04/16/12
I had appiled Kapton film, a stronger than teflon dielectric, across the flat washers surface that faces the transformer to keep it (the forces)from reaching, at least in large part, the surface area, of the washer. If you think copper would work better, I can try that but, I have had a bad sounding experience with copper, reflecting back onto the audio signal, audio signal is the key difference here and affecting it negativly (first postulated by Duster in a previous post, long ago). Not to say that that happens in all applications, but I've heard, what I think are the effects of the postulated reflection, and its not for the better.
Again, it is important to make a review of the laws of induction. An electrical field generates a magnetic field, perpendicular to the electrical windings, at least when AC is applied. Your primary windings in the transformer is AC and this directly applies. The magnetic field, in turn, generates an electrical field ad it is this field I am trying to address. Normally, the steel will carry the electrical field but because it has high resistance, it "slows" the transfer of the magnetic field. Use of a thin copper layer seems to "speed" up that magnetic field.
I have used copper tape to apply this to many things magnetic in nature, particularly mu metal and it gives a more lively sound with better transient attacks. If you go to various websites which sell mumetal "kits" for experimentation, it is one of their more consistent recommendations. Magnetic material needs the copper lining.
again, YMMV,
Stu
Unclestu, so what your saying is that I'm looking at this 180 degrees off. Rather than trying to reduce, block or impede the flow, I should use what its natural inclinations are, for the betterment of the sound. So I should, starting from the bottom-up stack the components as follows: Chassis (galvinized steel), Rubber (vibration absorbing material) pad, copper foil, iron plate, transformer, iron plate, copper foil, washer, nut, using nylon threaded rod through the center of the toroidal transformer. Is all this going to need to grounded separately? I would think not, because the transformer is grounded at the amps internal ground connection at the IEC inlet, I think that the gauge of wire used by the manufacturer might be of insufficient gauge though, I'll have to check it out. Is the use of two iron plate washers and copper foil, top and bottom overkill or is it the best of what can be attained, under these circumstances?
I would definitely NOT want any magnetic field to enter the chassis. Ever hold a nail to a magnet? You can pick up small steel objects significantly farther away since the ferrous nail actually carries the magnetic field and exerts that field farther away. You DON'T want stray magnetic fields around actual audio circuits.
I believe your proposed layout is how I would do it. Just ground the copper foil sheets. The sonic difference is subtle but audible. I believe the induce charge eventually builds up and it seems to make things sound "quicker" when it is grounded: not immediately but at least in long term listening, which is why I believe a charge can build up.
YMMV
Stu
unclestu,
There is about 6" between the transformers center hole and the inside casework of the rear panel. The backside (wire connection side) of the IEC inlet is about 1/2" from the transformers plastic jacket. The transformer measures 5 1/2" in diameter, yielding 1/2" clearence. That said, would it be better to have 5 1/2" steel discs, top and bottom or 5 3/4" steel disks, the extra hangover would/should pick up some of the residual periphery magnetism and keep it from effecting the surrounding storage caps. I could of course get 2 of each and use a 5 1/2" top or bottom and a 5 3/4" and use that top or bottom. I'm not really concerned about clearence, as much as, the possibility of arcing, should the clearence be insufficient.
Imagine the magnetic field of the transformer as a washtub full of water. Say you have two people 180 degrees apart and paddling the water in the same direction (clockwise or counterclockwise). You soon see a vortex in the middle. Try pouring additional water into the vortex and the system collapses. That's what happens when you place a magnetic material in the center of the toroid. The fields from the other sides, like the water actually fight each other and create more issues.
As previously stated, any ferrous material tends to catch magnetic field and retain them. That's where many issues come about. If you place, say a nail on a magnet, you will notice the tip of the nail will magnetically attract objects even further away than the magnet without the nail.
So, in order to limit the field of the toroid, the washer should not extend really beyond the edges of the transformer. The larger washer will actually extend the field further beyond the edges. The washer works by pulling the fields on top of the toroid closer to the windings. In doing so, the lines of force come out at the edges closer to the toroid itself, too.
Stu
I understand what your saying and when you explain it that way, it is quite clear. On a practiced level, the largest washer I can find is 3" in diameter from McMaster-Carr. I would think that the closest I can get to 5.5 inches the better but, like the vortex, its strongest at the center and as one leaves the center it gets progressively weaker and when one arrives at the outermost point of the winding, it is at its weakest with little residual. I would think that at the apex of the turn is where it drops the most, say at around 2 1/2 inches from center, (depending on enclosure thickness and number of turns), though the sea still churns less, than at the center of a whirlpool.
There are a few hvac/sheet metal places around that I can try, thanks for the suggestion and what about the galvinizing layer on the steel, any effect, probably negligable.
Thanks again for all your help, as well as, the education. Its greatly appreciated and I will let you know how it all plays out.
but wonder what the minimum order would be. Maybe you could ask for free samples, for "quality control".
You might know someone who works for the D.O.T., does bridge repairs, etc. (see description)
Thanks for participating in the discussion. Part of the reason for this whole experiment (?) is that there is one central transformer hold-down bolt with little top clearence, so stacking must be kept to a minimum. By using a spacer like this, I would need to use something smaller, yet big enough to hold this down as well. Thanks for the suggestion and I'll investigate further.
When experiences are shared, we all learn more.
Water jet cutting is expensive, simply because of the machinery involved and the set up required ( I ran a water jet machine for a while). You can buy one of those stepped drill bits ( which are not cheap either, but are very useful for drilling holes in chassis for tube sockets and such, but be sure to buy the single flute bits: the double ones work terrible). You can get up to 5/8 inch hole using those bits, and keep an eye out they go on sale often, and sometimes at automotive supply houses.
The galvanized layer is unimportant. After all, it is mostly tin, and the principle ingredient of most solders.
Good luck.
Stu
It would allow the transformer to move at some frequencies.
energy can not be created or destroyed: all one can do is to transform that energy. The application of AC on a power transformer has what they call a magnetostriction effect on the transformer core. The hum is is unfortunately part and parcel of using a transformer.
Personally, I find that transferring that energy to a chassis which contains your actual electronics is worse than isolating the hum where it is generated. That's probably one reason why separate power supplies often sound "better": the hum from the transformer is isolated from the actual electronic circuit.
Even with EI core transformers, a routine mod for me is to mount the transformer on rubber grommets. That additional isolation adds a degree of warmth to the component and gives a noticeable increase in midrange detail. This applies not only to tube gear, but also to solid state fully transistorized gear, too. Of course, there are alternate means of warming up a circuit design, and isolation of the transformer may accentuate the issue, so be aware.
YMMV, obviously...
Stu
I asked if he had ever used StillPoints isolators under large isolation transformers. He had and said it made a big difference. The StillPoints convert vertical vibration vectors into horizontal ones which can go nowhere and thus into heat.
use various footers under isolation transformer, however, my issue was using them under transformers in an electronic component chassis. My apologies if I didn't make myself clear about that.
In an electronic component with active circuit, motion is not very good. With tube gear, that would be rather obvious, but few realize even solid state gear sounds better if vibration is kept away from the circuitry.
Very early on, when Sorbothane first came out, I remember applying small bits, about a 1/16 inch square, to the tops of the TO-92 transistors in a PS IV preamp. The change in sound was dramatic: the characteristic "bright" PS sound became very warm and rich, and yet the PS had an external power supply housing the transformer.
Pondering over why this would be so lead me to dissecting transistors, and it was an education to do so. TO-3 types have tiny little wires jumping the leads to the actual transistor element, roughly a 1/4 inch square, and it is set in a hollow space, although early types are curiously fluid filled (heat transfer?). The fact that you have tiny wires attached to a basically a pure silicon element sort of makes every transistor a modified crystal oscillator to a certain extent.
Again, I would reiterate and say that it is best to keep any source of vibration as close to the source as possible. Diffusing the energy into other components is generally not beneficial for good sound, as that energy is changed in frequency and amplitude, but still present. If you are extremely careful, it is possible to transmute that energy into something outside of the audible bandwidth where it may be relatively benign, which seems to be the goal of most designers. Otherwise, you get an accentuation of the resonant frequency of the device in question.
Again, YMMV.
Stu
How difficult is it to re-thread a 1/2" portion of a nylon threaded rod? I'd like to go from an 8mm diameter rod down to a 6mm diameter rod for 1/2" and what would I need tool-wise? Should be fairly easy I would think as nylon is pretty soft.
Is a regular tool die would work fine. Sears, and other hardware stores sell them, Being that tools are often made in China these days, costs have been getting progressively cheaper. (Check out Harbor Freight). I buy Sears Craftsman tools because of the lifetime guarantee and because IIRC I paid about $100 for a complete set of taps and dies ( metric and English thread). The dies are available separately, BTW.
Incidentally, as long as you're not moving the component around much, I have simply used RTV silicone caulking compound to glue down the transformer. Just be sure to remember to replace the original bolt when shipping the component.
Stu
I too usually buy Sears Craftsmen tools, in large part because of the warranty and because of the close proximity to my home. Its nice to know that they (the dies) can be purchsed separately. Would I need to reduce in 1mm steps or can I go directly from 8mm to 6mm without creating a problem? Sears tool department does seem to be getting smaller as of late, and though Harbor Freight is a 30 minute drive I might end up there because of the decreased cost in purchasing the dies I need.
Many cautions have been given about shipping or moving the amps without the steel hold-down bolts being substituted back in, and as heavy as the transformers are, I can certainly understand why, as they could easily break loose. Caution noted and thanks again for your help.
I would take a bastard file and simply file off the thread for the larger diameter. That'll get you pretty close to the finished diameter.
Stu
You hear that manufacturers? We want miniature roller-block assemblies to put under our transformers. No joke.
Actually Norm, something like this already exists in the automotive industry. There is a bearing plate that goes between the top of a suspension strut (shock absorber) in your car and the underside of the shock tower of your car. These two plates have a race with small ball bearings in it. The purpose is to keep the suspension from binding when you turn the steering wheel, most importantly when the car is sitting still and you are turning the steering wheel, as in a parking lot. Forgive the simplified explaination for those of you in the know. Now all we have to do is try it. The size of the bearing plate might even be close to the size of my toroidals. I was in the shop when they replaced the front sruts on my daughters Honda Civic and saw them fall apart (178,000 miles) bearings everywhere, but new bearing plates might well be the trick, or something like them. Thanks Norm
In theory, a perfectly balanced toroid would have zero flux in the center where the bolts are usually placed. However, in the real world, things are never quite that cut and dried.
Lines of flux DO pass through the center region, and even if one argued a perfectly balanced winding and core (HA!) the bolt does not have zero diameter, and therefore, will be subject to some magnetic flux being present.
My personal theory about the reality is that the presence of a magnetic bolt OR a conductor, will actually draw some of the flux lines toward the center more than if there were no such material present.
A non-magnetic AND non-cnducting fastener (such as a nylon one) should prevent this and prevent any deleterious effects from occuring.
Note that use of a plastic bolt and nut, such as nylon, may require a larger diameter to still hold the transformer securely and safely, especially for shipping purposes. Other wise it might be a good idea to swap the original steel bolt and nut back in for shipping purposes, or when transporting the amp for any significant distance.
Jon Risch
The Mono-blocks I'm using each, have stacked 400 volt Plitron transformers. Total 800 volts per side.
They are mounted as follows:
from bottom up. Amp has 4 rubber feet (sitting on concrete basement) floor, then galvinized steel bottom plate (Amp Chassis), then transformer, 3 inch aluminum flat washer, 1/4-20 stainless steel flat washer, then 1/4-20 brass nut, bolt holding it all together and down tight is 14-20 X 6" long. Bolt comes up from the bottom, in other words, bolt head is under the amp, washers and nut are at the top of the transformers.
What I wanted to do is: Remove two front rubber feet and replace with 1.5 inch brass cones (sitting on/in Herbies Hushpuckies). Remove (or they can stay there) the 2 rear feet. Use 1, 1.5 inch cone (currently tapped at 6 mm) as the bottom nut, as it were, and a threaded 6 mm brass rod, topped off with a, and in this order, top of transformer, isodamp 3" round piece of damping sheet material, Kapton film, also 3" round, 3" stainless flat washer, brass or stainless steel 6 mm flat washer and finished up with a 6 mm brass nut. The third cone will be sitting in/on the Herbies Hushpuckie as well.
By doing this the bulk of the amps weight, and the more vibration inducing portion of the amp will be resting on the rear and last spike in the configuration. I may have to pack out the extra space in the center of the transformer hold-down bolts attachment hole with ? Brass tubing? Teflon tape, Kapton or Teflon sleeve tubing? because the 6 mm rods diameter is less than the holes diameter and I want to remove any kind of "slop" space in there. Any ideas here would be good, about what to do with the slop space. If I have left anything out electrically, please advise. Sorry my plan is sooo long but, its involved, as you can see. Thanks.
Al conducted tests of ferrous materials placed in the magnetic field of current carrying conductors. I remember him speaking of a piece of steel being essentially a one turn inductor.
nt
Anything into which you can induce a current will act as a magnet....
Aluminum? yes. Brass / Bronze. For sure.
I like the nylon idea for those who have such concerns.
Too much is never enough
I have swapped to nylon threaded rod with similar results. My initial objective was to see if I could reduce stray voltage on the chassis.
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