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In Reply to: RE: Multi-layered, Adhesive-backed Felt Surrounds for Cone-Speakers posted by Dryginger2 on March 27, 2015 at 13:56:04
Nice tweak, well documented in hundreds of applications and even some commercial products. Yes, Madisound is very helpful.
I see a rather glaring incongruity in your pics: why would someone who relentlessly hunts for places to damp vibration leave one cover completely off a piece of gear (can't tell: amplifier?) and the other covered with what appears to be a piece of transparent plastic (!), exposed to all air borne vibrations? That plastic probably vibrates like a drum head. I notice an effect when playing my monoblocks with and without their covers: always better with covers in place, even though they're only thin gauge aluminum. I have also damped the cover of my passive preamp and Marantz SACD player with positive results.
What happened to all the hideous rope caulk you had gooped onto your speaker baffles a month ago?
Peace,
Tom E
Follow Ups:
Tom E, your posting exemplifies the kind of 'peace' intentions of the other side in the current 5+1 M.E. negotiations:-)!
The only thing that matters to me is to keep raising the sound quality of my audio system - loyalty to a conflicting past practice out of some fear of appearing embarrassingly inconsistent would be self-defeating.
Tried the rope caulk tweak advocated by UncleStu around the outside of the speakers and ultimately decided that they contributed too little sonically for the aesthetic cost to my eyes. Still use his rope caulk tweak inside and appreciate his generosity of spirit in sharing his breadth and depth of knowledge.
Needless to say, our varying ears, audio equipment, and listening environments all too often lead to different conclusions. Testing the sound with the Denon CD/DVD 2910 case cover on and off here revealed that the substitution of thick perspex lined along the edges with cork to prevent vibration led to a less fragmented, more solid sound. Denon attempts to suppress some of the vibration to which their thin aluminum cases are prone by doubling up from the sides to the bottom and from the cover to the sides but it is still a flimsy vibrating case in my opinion. Having ready access to the interior also proved practical.
The case of the integrated LFD LE4 amplifier is a much more solid and serious piece of kit although the aluminum back plate could be a great deal thicker and more rigid. Once again I found the sound improved with the cover off and it also provided immediate access to the interior. It runs so cool that the cooling aspect beneficial to the Denon was not present.
If you have not yet substituted plastic screws for every single stainless screws in your monoblocks, then you still have a heavy curtain of EMI distortion to remove and will be pleasantly surprised at the resulting increased access to the music. Visualize the lost definition of skyscrapers in morning mist and contrast that with their sharp outline in the midday sun to get the idea. (The only component that does not benefit from the substitution of every single machine screw is the DVD player in my experience.)
Have a great weekend!
DG
Please see the moderator's (Jon Risch) comments about twenty posts down.
Please don't do this plastic screw tweak to ANY metal enclosure, especially if you have children whom you would like to see grow to adulthood. If electrocution is an acceptable risk, as it seems to be for some, proceed.
Use one brass screw per panel and it will do grounding as effectively, although not as mechanically as rigid. Brass, being more conductive than ferrous material, including stainless, will speed up any "eddy" currents and any extraneous voltage on the very slim chance that the chassis picks up voltage from say a shorted wire......That should actually be safer than using ferrous screws
If really neurotic, take a screw hole and run a ground wire to the central ground bus or the power inlet ground terminal from each panel with a nut. Many panels have additional screws for mounting switches, connectors, as well as heat sinks. Simply buy a longer screw and a nut to secure the wire. sometimes only a nut is required. Brass preferred, of course.
Using wire will make the sound better already as the copper is significantly more conductive than the steel panels, and, unless you have a Counterpoint unit, the chassis is not likely to be copper plated. Steel has quite a high resistance. It is better to situate the ground wire farthest away from the transformer on the panels, BTW, as the field is pushing away from the transformer and has a tendency to "wick" the magnetic field in that direction and electrically induced current will move in that direction.
Magnetically, the transformer's magnetic field is entering the chassis. Again the magnetic field "likes" to stay in the ferrous material and so does "work" in moving through the steel. With the magnetic field comes an electrical inductance which actually is induced by the magnetism moving through and creates a certain amount of voltage and current. Draining this electrical component is quite beneficial to sound as Counterpoint discovered. They also wrote a "white" paper about the subject and if you scrape the paint off their amps, you will see copper plating under the wrinkle finish black. Claim was the highs were significantly improved, BTW
Running such ground wires also works for metal equipment stands and metal speaker stands. The AC fields present on the components of both do generate a small current and again grounding them seems to "speed" up the sound as the Magnetic field is attempting to do work within the metal platforms and legs. While trying to move the steel component , it really can not because of the mass involved and thus the "work" being exerted is literally energy wasted. The magnetic inductance still produces an electrical field however, and draining any such results will help lower the induced currents.
I normally run a ground wire diagonally across a tall rack from say left top corner to right lower corner as the steel has considerable resistance. MY racks are 5 feet tall and 22 inches wide, BTW. This way the "eddy" currents are more equally drained and there is less of a voltage differential from top to bottom
OF course,if you are already neurotic about the metal chassis, metal racks only one step away and since power cords are often snaked through them, something to consider also, particularly when employing certain makes of audiophile PC's. My racks are grounded to the third Ac terminal not because I am especially worried, but to better sound.
AS always YMMV
First two paragraphs are good advice, in case anyone couldn't figure it out themselves. Using an existing fastener for grounding purposes works only if it is conductive to the panel, such as a screw in a tapped hole. A through bolt or nut on top of a coat of paint or anodizing will be insulated, ineffective. Rarely, heatsinks are intentionally insulated from the chassis, so be careful there.
All of those connectors and some of those switches and especially PCB's would probably be better served by non-ferrous fasteners. That's where I use brass or non-magnetic stainless. I suppose you could get away with nylon there, knowing that at some time it might fail.
Suppose a couple nylon bolts sheared, or the mounting hole corners broke away, or the board itself broke (ever ship or drop anything?), and a PCB with power traces contacted the enclosure. You would be protected by the safety ground unless the enclosure was not completely conductive. Acceptable risk? Neurosis?
Better yet? Apply a few irregular shaped pieces of high quality damping material (nothing flammable or containing uncured silicone) to large unsupported panels and around signal connectors and PCB mounting bolts. Leave the rest of the chassis alone unless you know what you're doing.
Peace,
Tom E
Most knowledgeable DIYers know about scrapping away paint where chassis grounds are desirable, but you're right in repeating the advice, as it doesn't hurt anything.
Very serrated star lock washers will usually bite through the paint when used, but it is good to remove after initial tightening to double check.
I like to use machine screws as you can torque them down tighter. One benefit of China is that tap and die sets are relatively very cheap these days and for the hobbyist perfect for occasional use. Just don't use on stainless steel chassis unless you have replacement taps. Stainless is extremely " sticky" and tends to both grab and break taps or dull them quickly even with gobs of cutting fluid.
"Tom E, your posting exemplifies the kind of 'peace' intentions of the other side in the current 5+1 M.E. negotiations:-)!"
Please leave the politics at the door, whatever your stripe.
Go post at Fox.net or CNN or whatever, but politics is bullshit and should NEVER be mixed in with audio. It has a 'polluting' effect. Yuck!
PUH-LEEEEEZ!
Winston,
You may be counted on to emotionally over-indulge when expressing your confusion over a humorous reference to contemporary hypocrisy regarding the use of the word 'peace'. If you are attracted to pollution, count N.Z. sheep! Personally I prefer to focus on music, tweaks and a little humor...
Thank you.
DG
Sorry, Mr Ginger, but this is mostly nonsense. Good that you are able to realize mistakes and change course, but progress does not depend on contradictions. Progress is made by objective evaluation of experimental data which should include careful observation (listening) as well as measurements. I am not trying to make peace here, but trying to clarify things for people who may be impressionable enough to believe some of the stuff you and your tweaky buddy post here.
When you recommend something as drastic as covering the front baffle of your speakers with caulk and then realize how ineffective that really was, you should at least have the decency and guts to come back here and tell people you gave them bad advice.
Now you've removed a metal cover from the enclosure of your budget DVD player and replaced it with plastic and claim it improves the sound, as does completely uncovering your integrated amp. I can't dispute that, but what seems even more important from your description of these "improvements" is that you now have "easy access" to the inside so you can endlessly fiddle with stuff that probably doesn't need to be fiddled with. The greater definition you think you're hearing could be high frequency noise or microphonic capacitors vibrating.
How long before you post pics of your system with thick metal covers on the enclosures, advising everyone about the new found clarity and pristine highs and lifting of obstructive morning mists from your system with solid aluminum covers on everything? Some of your tweaks are about as reliably effective as the wind direction in March. Others make sense and might actually be useful. Try to discern the difference before posting here.
Replacing metal screws in an enclosure with plastic ones to remove a "heavy curtain of EMI distortion" is hogwash and could even be dangerous. What you might be doing is breaking the path of safety ground (and screening from EMI) from one panel of the enclosure to another, endangering yourself and anyone else who touches your system while plugged in. If you want to do such stupid things and believe they're effective, that's fine, but please don't advise other people to do it without warning them.
After flipping many expensive components within my system over a long time, I built my own monoblock amplifiers, power cords, IC's, speaker cables, three-way speakers and subwoofer, and their passive and active crossovers, which took years of research and experimentation. I may have spent as much money just on trying different capacitors as you have on your speakers. My system possesses a level of clarity that many people will never know exists. There are no heavy curtains to be removed by using plastic screws.
Tom E
nt
Edits: 03/30/15
Tom E,
So sorry that you are evidently having a bad day. King Canute also struggled with reality and his credibility never recovered from commanding the incoming tide to reverse its course long before high-tide. And he had the wealth of a kingdom to make him right!
Tant pis.
DG
I know this Pi$$ed you off before but I'm saying it again, I can't hold back.
You must have one crappy system, environment and layout to achieve such fantastic gains each and every time you try something in name of a tweak. What is more incredible is the frequency that you come upon such discoveries. I reiterate, time to try a new system, environment or layout.
BTW how do you know that plastic screws cut down on EMI? Last time I asked an oscilloscope was a NASA satellite to you.
Mike,You contradict yourself. We all have different styles but you are not just objecting to my style, are you? You are curiously objecting to the the very same content for which you earlier thanked me.
RE: Multi-layered, Adhesive-backed Felt Surrounds for Cone-Speakers, posted on March 28, 2015 at 09:46:50 Uncle Mike:
"Good to know. I have been looking for something to replace the decayed foam on my AR9s. Thanks"This website is not to be mistaken for a lamppost and abusively marked with personal self-dissatisfaction.
DG
Edits: 03/28/15
"This website is not to be mistaken for a lamppost and abusively marked with personal self-dissatisfaction."
Best line I've heard in years. When I caught my breath from laughing I read it to my better half and she had the same reaction. If it's original you got a nice turn on it and if you are passing it along you have my heartfelt thanks.
EMI is an, er, 'interesting' topic, it's right up there with shock and Vib. as favorites of those in the electronics biz. Right up there with a broken leg.
Putting a plastic lid on a CD player is probably a good thing, let out some of that energy from the servos and logic before it sneaks into the D/A or analog chunks. I don't know why plastic (Nylon I presume) screws helped. At a guess it may have "de-Q'd" (partially decoupled) some of the chassis resonances. Nylon at least is pretty springy and low tension. But they may have had an effect on circulating currents also so you may be spot-on.
I think that you are learning a lot and having fun and I appreciate you sharing it with us. Home audio is interesting on so many levels that it makes a great hobby. Superficially simple yet actually very tricky which I believe is due it's wide bandwidth and our amazing signal processing...
Best, Rick
Rick,
Thank you for your support. During WW2 it is said that the Labour Member for Bradford (named Mr. Rayling) interrupted a Parliamentary speech of the British prime minister, Sir Winston Churchill, by standing up and shouting: "You dirty dog!" To which Sir Winston retorted: "If the Honorable Member will come outside afterwards, I'll show him what dirty dogs do to railings!" - a response that reduced The House of Commons to hoots of laughter.
Suspect that substituting nylon/plastic for stainless steel machine screws may be beneficial even with external transformers but it certainly is with internal Toroidal transformers even, I found, if some of the original screws demonstrate little to no attraction to a magnet. My assumption (which I hardly dare share here;-) is that the proximity of each bit of stored magnetism near wires and components interrupts the smooth power flow (not being technical I better not refer to jitter) as the resulting improved access to the music is most rewarding to those willing to go through the aggravation of sizing and buying the plastic/ nylon substitutes from McMaster-Carr or wherever. The sonic gain from the substitution on the LFD LE4 is at least as great as substituting brass for ferrous wood screws on Vienna Acoustic Mozard Grand speakers for example.
With best wishes,
DG
It took me a lot of time to wrap my mind around magnetism, particularly that generated by AC. Have to remember the fields are 90 degrees to the current flow and circular in nature to the conductor. In addition, for lack of vocabulary, there is a sort of vector, in that the magnetic field is moving in the direction of the current flow. I like to conceptualize it as a sort of screw shaped field turning in the direction of current.
When you have things like toroids and speaker magnets, then you have to think in 3D, which, when analyzing, makes things more difficult.
I believe you are very correct in seeing ferrous or conductive screws interrupting that smooth flow of magnetic fields. The old school experiments with ferrite powder on paper and placed over a magnet in order to see the lines of force comes to mind. Place a screw 90 degrees to the force lines and the field becomes extremely distorted (Lessemf.com has some neat toys to examine these fields using encapsulated ferrite powder.
Magnetism prefers to travel in a ferrous object, hence the attraction (and the need for a "keeper" on a horseshoe magnet). Trouble is when entering ferrous object, the magnetism doesn't quite want to leave, and something like a screw tends to retain the captured field.
In a speaker, the retaining screws in the frame creates a sort of spike in the toroidal magnetic field generated by the magnet. The field enters the screws and stays there resisting leaving. The field develops lobes, sort of like a clover leaf.
Now since magnetic fields also induce an electrical field ( and vice versa) brass screws eliminate the magnetic retention but also allows us to ground the more conductive brass allowing any electrical field to drain. Nylon or plastic eliminates both of course.
Remember you can not separate electrical and magnetic induction. At best you can channel them, though.
Let's at least go back to the fact that Dryginger says his chassis screws were made of stainless steel, which is nonmagnetic. But yes, you can counter that some stainless steel is faintly, very faintly attracted to a powerful magnet, because of its ferrous content, however low that may be. Still, there is no scientific logic to your post, and you've got Dryginger as a follower. Just looking at DG's system, do you honestly believe that it can reveal what must be the very very tiny effects that you describe, even if one were to accept that such effects really exist, which one shouldn't do? I apologize for my tone. I do find myself in agreement with some of your ideas, but not this one.
Experiment: put a strong magnet near a piece of iron. Other ferrous objects will then be seemingly attracted to the piece of iron. When you remove the permanent magnet, that piece of iron will be in one of two states; it will be magnetized itself but very weakly or it will be completely nonmagnetic. The weakly magnetic state will wear off in a short while. So, what is the evidence that even a ferrous screw will "hold on" to magnetism? And why should we care, if there is no coil of wire or other conductor moving across the putative magnetic field in the vicinity of said screw, which anyway will most likely not be made of iron? If one is concerned about the toroidal transformer, shield the damned thing with mu metal and be done with it.
have you used Mu metal. I have mu metal foil and sheet dating back to the mid 90's and have extensive experience with mu metal. Been playing with metglass recently, and ferrite powder too.
I very seriously doubt if you have ever used mu metal, or the statements you allude to would be woefully inadequate ( to say the least).
Experiment 1. take a magnet and place it under a sheet of paper or cardboard. Sprinkle some iron filings or ferrite. cardboard over the magnet. Gently tap the cardboard and you can see the magnetic lines of force appear. Now place a nail or anything ferrous on the cardboard an tap again. What happens to the lines of force? This was a fourth grade science experiment IIRC.
If say the nail is aligned with the lines, the lines are greatly extended. If crossing the lines of force at 90 degrees, it truncates the lines.
Again magnetism prefers a ferrous object to project its field. That being said you to need to complete the circle so to speak. AN EI transformer lamination is proof of that. However it is not possible to have a completed magnetic path all the time. Speaker try to do so with the pole pieces but there is leakage from the magnets that extends outwards into the cabinet.
A ferrous based screw tends to capture the magnetic field and tends to retain it. There is a bit of resistance in reentering the air.Use the iron filing test and you can see this
So what? I don't think I argued against anything you've written in your response, except I would take issue with the notion that magnetism is a force yearning to be free, as you describe it. By the way, what about magnetic leads on resistors and capacitors? If you're going to replace all the darn screws, you've wasted your time if you don't also replace all those other magnetizable elements. And in DG's amp, the screws were stainless, whereas it's highly probable that his amp still contains capacitors and resistors with truly ferrous leads.
I asked DG whether he had actually measured field strengths in and around his amplifier before vs after changing from SS (not iron) screws to plastic. I doubt he's done that, but have you? That would tell both of us something.
C-mon Lew, it may have been some time, but the magnetic lines of force I refer to want to complete the loop from north to south poles of the magnet, fundamental for any magnetic object. Capture a portion of that loop and the field still wants to exit to complete the loop. That's how magnetism works. You don't only have a single ended magnet, say north pole, only you have TWO.AS for leads and such: ask yourself, which is easier to replace? But I seem to get the feeling what you are stating that the leads on resistors and caps are more important for EMF. Since this is YOUR contention (seemingly) why not buy a gaussmeter and measure it and report your findings? Why bother to state your unsupported speculation.
Also ever wonder why some manufacturers place their transformers outboard?
PS I do have a Lakeshore gaussmeter, BTW, and did some measurements long ago but I did not record any numbers. Why don't you get something similar since you are so adamant about the subject,
Edits: 04/02/15 04/02/15
You wrote, "C-mon Lew, it may have been some time, but the magnetic lines of force I refer to want to complete the loop from north to south poles of the magnet, fundamental for any magnetic object. Capture a portion of that loop and the field still wants to exit to complete the loop. That's how magnetism works. You don't only have a single ended magnet, say north pole, only you have TWO."
Where did I say there was only one pole to a magnet? What's lacking in this response is what I am looking for; how does the issue of whether magnetic lines of force "complete a loop", or don't complete a loop, affect the sound of the amplifier under question, where the magnetic field you posit has to do with the minimal ferrous content of the chassis screws? They are all at ground potential, or should be.
You are SOOOOOOO correct. Something is definitely missing, and I find myself trying to explain fundamentals to someone who wishes to ignore them.Let me end all further discussion with you with several points. Nothing personal here, It's just I have better things to do.
Magnetism does NOT extend only a few inches away. Again pick up those children's toys with ferrous flakes and see how far away you can extend the range of the toy flakes. That's one blatant example, another is sit back and look at the range of the earth's magnetic field. It may be weak but it extends many, many miles....
Now, If the loop is not completed, magnetism, as a force, will be exerting induction WITHIN the material the field is captured in. The natural inclination is magnetism wished to complete the field or it exerts an electrical component to the material holding it
If you don't understand induction, please, please review your 8th and 9th grade science......
Again nothing personal
flakes,It's pretty impressive considering you are also fighting gravity.
Edits: 04/03/15
that was pretty f-ing personal.
Insult when you cannot explain is always a good way to end a discussion. Maybe you don't understand my question: What is possibly affected by the tiny magnetic field possibly radiated by nearly non-ferrous screws holding together a chassis that should be at ground potential (not to mention, what is there to magnetize them?), and why do you seem to care less about ferrous leads on resistors and capacitors in the same amplifier?
Like most other forces of nature, magnetism follows in inverse square law, the force will be inversely proportional to the square of the distance. Thus a tiny force like the one you fear will be really really tiny very quickly as you move away from the magnetized screw.
1. Magnetism induced in ferrous material constitutes work being exerted by the magnetic source: hence we have something like transformer laminations or motors(electrical, of course ) for that matter.
2. Inverse square law ONLY applies if the magnetic force is in air. All bets are off if the field enters a magnetically permeable substance: Check out the specs for Mu metal and metglas.
3. Whether or not magnetic leads are more important is totally immaterial to the discussion ( if you care to call it that). Magnetism in the leads does not really affect the fact that magnetism in the chassis still exists. Want to eliminate the magnetic induction?: turn your gear off....the entire planet emits a magnetic field, you don't see me trying to eliminate that field even though it does have an effect on electronics (last generation Panasonic and Sony CRT sets had adjustments if the set screen was oriented n/s or e/w).
4. In tweaking, one does what he can: cost and labor of course being important parameters to consider. What's easier: changing screws or changing resistors? How many resistors have you changed in your lifetime? I've totally rebuilt several preamps, QS full function as well as CJ's but the cost is extremely high unless you are doing the work yourself. Couple with the accumulating of the necessary values, takes a lot of time.
5. I am not an armchair theorist. I try things, and, yes,I have tried non ferrous leads, having custom capacitors literally built to my specs from Southern F-Dyne. Do you just catalog search or do you actually try things? My recommendations are not theoretical but based on actual experience. Theory comes only after extensive experimentation. If I haven't tried a tweak I don't comment about it, as I really don't know.
And with that, I bid you adieu
Lew,All I did was test every manufacturer's amplifier SS screw against a magnet to feel the level of attraction as earlier described and was surprised that only 20% showed no attraction/ repulsion whatsoever. Interestingly the substitution of nylon/ plastic for those 20% contributed as much proportionate sonic improvement as the responsive 80%. Don't know if that helps...
DG
p.s. Surely magnetism in amplifiers is a force that needs to be contained immediately around the Toroidal transformer by a shield but denied freedom to subversively degrade component performance through AC/ signal wires and SS screws? Sound improvements from twisting positive/ negative wires, enclosing ground-wire in 3M AB 5100S, and switching out the screws acting as disruptive local magnetic storage areas indicate that to me. (Incidentally the necessarily untwisted nature of ribbon cables has long seemed a point of vulnerability...)
Edits: 04/02/15 04/02/15
Thanks again for your very reasonable nature. A lot of guys get pissed off during discussions like this, where none of us really know the others. The subject of EM is much more complex than we are making it. I am not saying that it is not desireable to shield from EMI; I am only saying that I doubt your chassis screws could possibly have been doing much damage as generators per se of EMI. Certainly nothing that would be audible in your system. You may say that you did the work and hear the difference. To that I would have no argument except to say that there is such a thing as observer bias, and it's very powerful, especially when a guru like Uncle Stu endorses the work. In the end, you have a subjective impression. But to prove that I am wrong, someone would have to measure the EMI fields in and around your amplifier before vs after the screws were changed. Finally, this hobby drives all of us to do kooky things; I am hardly perfect in that regard.
Lew,
Appreciate the calm, logical place from which you speak, and, given the strength of your belief, can quite understand your natural desire to reject my experience as real. It's the only way to square the circle...
So consider, firstly, that this is not UncleStu's tweak but a cross-application of my own from his speaker basket tweak to the amplifier from which I literally had no expectation prior to testing. Secondly, a discerning audiophile (well-developed hearing skills), familiar with my system sound, immediately volunteered without prompting: "This is exactly like live music!" an opinion that did not change over time. He subsequently listened to the sound from the first above version of these felt-surrounds and was quite impressed by the treble focus and base de-fragmentation but commented that the sound-stage was too narrow. As a consequence I followed UncleStu's advice on enlarging the apertures and followed my own hunch in slightly reducing the number of layers which did the trick as that fellow later agreed.
The only thing I trust is what I hear with my own ears and testing, needless to say, produces infinitely more failures than successes. UncleStu tends to recommend tweaks whose sound improvement I can replicate here but that is not invariably the case. And I have no expectation either way and routinely express respect and gratitude to him because tweaking by testing and the ear is an under-appreciated path here from which he has generously contributed for a long time. To me this path is the true north since the alternative of borrowed opinions and technical explanations can be unreliable and often left me going around in logical circles at the beginning.
These two tweaks are real and work well in reality even if some aspect of their concept or implementation starts in the imagination!
DG
Lew,
Your skepticism is understandable. And I would be a conservative member of the large majority had not three respected audiophile manufacturers with their own companies independently told me to ignore the published and widely-shared 'technical' assumptions that limit what's possible to intellectually accept and establish my own knowledge based on what I heard with my own ears during testing. So when it comes to reporting results, I'm not on UncleStu's side but frequently read that we hear the same outcomes despite different equipment in different environments.
After substituting brass for ferrous speaker wood-screws led to a substantial lifting of audible distortion, it was natural to think of checking whether this kind of advance might be duplicated elsewhere. It was also human nature to logically disbelieve that it possibly could. After all I 'knew' from Tweaker Asylum postings that the magnetic content of stainless screws was low to nil so where could any such benefit possibly come from? Long story short, I bought the plastic machine screw replacements of the many required European metric sizes/ dimensions over many weeks and would have not continued beyond the first week had the distortion-lifting benefit of switching out the large case screws not been encouraging. Generally speaking, the proximity of small screws to sensitive components meant that the substitution of plastic for each SS screw, regardless of size, had a somewhat similar benefit.
You may not be familiar with the highly-resolving LFD LE4 Integrated Amplifier, widely respected in the industry and used by Sam Tellig as his reference I believe. It's a product evolved over decades by the uncompromising Dr. Richard Bews who designs/ hand-builds his products using simplicity as his guiding principle while stockpiling the highest quality components to install, reducing wire runs to a minimum and never entertaining remotes that degrade sound quality.
If you are temporarily willing to open your mind to the possibility of a major improvement that logic seductively causes it to resist, I encourage you to listen to the difference in sound after substituting plastic for your amplifier case's SS machine screws. I can only guess at reasons why it works but work it most certainly does. Otherwise I would not have bothered to go through the inconvenience and cost of switching out every single screw but the amplifier AC input ground screw. Have done many tweaks and it was one of the most effective.
DG
When pointing out Tweaks that involve potential AC line issues, one should always issue a disclaimer and warning about the hazards and dangers associated with those kinds of tweaks.
What Dryginger2 proposes, with replacing the SS screws that hold his chassis panels together, with plastic ones, MAY allow one or more panel to become dis-connected from the safety grounding that is is supposed to have per UL, etc.
If this is indeed the situation, and it is not uncommon for a manufacturer to use conductive screws to complete a safety ground path, then replacing all the chassis is screws with plastic screws COULD create a situation whereby one of the panels could present a serious shock hazard.
While this may not be a high percentage likely hood, if there is ANY chance that replacing the screws with plastic can present a risk of electrocution, it should be noted and appropriate precautions taken.
The fact that Dryginger2 noted that his CDP presented a "tingle" when touching one if it's part after he modified it with plastic hardware is a clue that there may be in fact a dangerous potential for AC line current flow through his body, instead of into the safety ground as was intended by such grounding and safety precautions taken by the original manufacturer.
So everyone should be aware of this potential for serious harm, even life threatening harm, and proceed with caution and all possible safety procedures.
If you do not realize that such things can occur when doing these kinds of mods, and do not bother to tell folks that there is a potential issues and safety concerns, then perhaps it would be a good idea to not post them any more or recommend that every one try them to see how they sound, as a dead audiophile listens no more, and we need every one of us who is left to carry the torch on to the younger generation.
Jon Risch
for the lengthy and very civil response. Try upgrading your coupling capacitors from whatever they are now to something better. For example, if your device uses metallized film caps or electrolytic capacitors, in the signal path, then upgrade to true film and foil capacitors of high quality, say polystyrene or teflon. The difference that will make in sonics will dwarf anything possibly due to changing chassis screws. And it's a much easier thing to do.Further, while I don't believe anything is achieved by replacing ss screws with plastic ones, except a loss of structural rigidity, my main problem is with the idea that because we have electromagnetic theory on one hand and ss vs plastic on the other, the aural benefits one imagines are ascribed to something having to do with electromagnetic theory. Have you or has Unclestu actually measured the EMI in and around an amplifier before and after the screw replacement? If so, is there any difference? That's what I would like to know before I connect A to B as cause and effect.
It's probably not a good idea to use Sam Tellig as an authority on excellence in audio equipment, as Sam himself takes pride in being "the audio cheapskate". His systems are never more than mid-fi, which is fine for him and anyone else with a limited budget or limited aspirations, but not a benchmark, exactly. The LFD LE4 is a small solid state amplifier module which offers the primary advantages of small size and low cost, is it not? What makes it so great? I know of one guy who used it or tried to use it as the core amplifier of a turntable motor controller, where it's only used to amplify the set AC frequency of the controller. (I may be thinking of another device, but that's what I remember about it.) In amplifiers, I don't do solid state except in one of my two systems where I use a vintage Threshold amplifier to drive woofers.
My bad. LFD LE4 is an expensive integrated amplifier, not a cheap module. Sounds interesting.
Edits: 04/02/15
No one can argue that you hear what you hear. Same for Stu.
As remote as the possibility is, there is the slim chance that one of the panels of your amplifier could become electrified with line voltage. There should be a safety system in place in the form of a low resistance connection of the metal enclosure to earth, which should draw enough current to trip a breaker. If that safe path is interrupted, the next path is through any conductive element that comes in contact with an electrified panel of the enclosure, such as a human. Without the safety ground in place, there is no way to know such a condition exists except by receiving a shock, the severity of which cannot be predicted.
Before you promote this tweak any more, please do us all a favor and test the continuity of ALL of the panels of your modified amplifier to each other, especially whichever one has the earth ground bolt in it. You can use an ohm meter and read actual resistance if there is any (a fractional amount would be safe), a continuity tester, or even a flashlight bulb, battery and some wire. There is no cost to do this, so it fits your requirements.
If there is not continuity among ALL panels, please promise to stop telling people to do this. If there is continuity, I promise I'll stop being critical of it. If you ignore this third request to address the safety issue, you will divulge something crucial about the sincerity of your pledge to help audiophiles realize better sound.
I have one more question: did you test the screws you removed to see if they were, in fact, magnetic? I am not demeaning your tweak. I use only non-magnetic resistors, and my tweeters and midrange drivers are mounted with plastic bolts. I'm not sure something as insignificant as chassis screws can contribute, but you hear what you hear. Unless you're dead.
Peace,
Tom E
Tom E,
Yes, I did expose all the original manufacturer's screws to a magnet and was surprised to discover that three-quarters showed an attraction, perhaps a third as strong as had ferrous screws. Since this was a cross-application exercise from UncleStu's speaker tweak, I started off with brass screw substitutes for case machine screws but their presence degraded the sound by changing the tone. So then adopted nylon/ plastic for all machine screws and was apprehensive of their capacity to resist stress. I need not have worried as, despite regular screwing/ unscrewing the plastic/ nylon machine screws of all sizes and holding the unit upside down/ on its side for access, the screws did not sheer with one exception. I was tightening a screw into a screw-hole where, unbeknownst to me, there was a remnant of Teflon tape whose added resistance caused it to snap. Thereafter I took great care to inspect and clean all screw-holes.
It was frequent testing of the warmth of the LFD LE4 heat-sink with my fingers many times daily over many days before I concluded that it was safe to substitute plastic/ nylon for SS machine screws there as well. Since most amplifiers run hotter, that is not a safe application that can be recommended for most users.
Am unclear as to what you want me to do with the electrical testing because that is outside my experience/ have no equipment for solder for bulbs to wires to batteries and must now sleep. With the slightest electrical concern, I simply detach the components concerned from the circuit. Much appreciate your spirit and will do what I can that I do get to understand and does not cost much money. (I find that the AC internal ground is tightened directly against the case by a plastic/ nylon screw with a brass washer in between the ground and the plastic screw-nut.)
Take care,
DG
Interesting that some screws are magnetic; others, not. I can see screws that hold PCB's in place might have an effect on signal, but probably not the chassis panel screws. They're just too far away and too small to have any audible effect.
If you substitute plastic for metal between panels, then there is a good chance of breaking the path of safety ground. If you don't understand that, then quit messing around with it and retract your previous recommendation and put the metal screws back in.
If the panels are coated with paint or anodized, they will not conduct from one panel to another without conductive screws inserted into bare metal threads. You put Teflon in the holes? Get all that shit out of there. Put the plastic screws in, if you insist that it makes such a difference, and test for electrical continuity from the panel that contains the ground bolt to all the others. You will need an ohm meter, available for a few bucks, or a continuity tester, usually a feature on the ohm meter or sometimes available separately, or you can make your own continuity tester with a battery and flashlight bulb. No soldering needed. Hold a wire against one end of the battery. Hold the other end of that wire against one terminal of the bulb. Now hold a wire against the other end of the battery. With your third hand, hold the other end of that wire against an enclosure panel. Your fourth hand holds another wire against the ground bolt panel, and the other end of that wire against the other terminal of the bulb. You should have a circuit of
battery-wire-bulb-wire-grounded panel-different panel-wire-bulb-battery.
If current flows through two different panels and lights the bulb, you have continuity and the enclosure is safe and I will finally leave you alone. If the bulb doesn't light, replace the metal chassis screws and quit while you're ahead and alive. I suppose you could try the test with the metal screws in place, just to see if you were doing it right or I'm full of shit.
The only other way to connect panels is with a wire firmly attached (screwed) to a conductive surface on each panel. Or you could try scraping any coating away where panels touch. This is a bit risky, and might not be UL approved if that sort of thing worries you.
Of course, all this is true only for enclosures with exposed metal surfaces. Wood is good.
You might play your stereo for a hundred years and never develop a fault. You might play a hundred stereos for a hundred years and never have a fault. You might turn it on tomorrow and get an unpleasant tingle or thrown across the room. That's why every metal part of it should be grounded.
Peace,
Tom E
Tom E,
Thank you. The risk factor is very small as you yourself stated and I recognized this morning that this particular safety concern is a monkey on the shoulder of your multi-handed anxieties and that's where it should stay. So, being technically qualified, please test it and report back to the forum (nobody will do a better job, you will be fair AND your sound will benefit).
I have for various reasons touched most parts of my amplifier under power since substituting plastic machine screws and never experienced so much as a tingle. Whereas the Denon CDP/DVD 2910 with a two-prong plug/ no ground by design and the substitution of very few plastic machine screws frequently delivers a tingle when touched during operation. For that reason I turn it off/ disconnect it at night or when absent.
Am sincerely looking forward to reading your report.
DG
I am reporting you to the moderators. Your suggestions are dangerous and it is a liability to Audio Asylum to allow you to post here.You are a dangerous fool.
Regards,
Tom Ernst
Edits: 04/05/15
how all the naysayers have to to do is to kick back and offer experimentation: they never need to experiment on their own adur to their intellect.
oh well c'est la vie
Hey, it's not my tweak, so it's not my responsibility to test its safety. Got that? I'm trying to prevent someone from being electrocuted or at least shocked or burning down their house.
I am not a naysayer. Got that? This is really starting to piss me off.
If someone substitutes plastic chassis screws for conductive metal ones, as DG is promoting, and they break the path of safety ground from one panel to the safety ground post in a different panel, they may be intentionally defeating a safety feature and there is a risk, albeit a small one, that someone could get hurt. If there is still a conductive path, then there is no risk and I'll gladly shut up. The only way to determine that is by testing for continuity from one panel to another, ALL of them. I do not need to perform the test because my enclosures use horrible, distorting, crude, magnetic, conductive screws. My stereo sounds like shit because of it, but I won't die from touching the enclosure.
I am trying to educate the man and warn others, and you make snide remarks. You want to ignore liability, fine. Someone's lawyer will snap you, and possibly AA, out of your fantasy tweak world pretty fast.
Do you know the difference between EMF and RFI?You do realize brass screws are more conductive than steel or stainless, right?
Do you understand Faraday's laws? I can reiterate them for you if necessary, BTW.
Funny how old tuners from the 60's used expensive copper plated chassis, enh?
Oh yeah top of the line Sony and Pioneer digital machines use copper plated screws for assembly tooAlso you use non magnetic screws ads hardware already for your speakers. Why shouldn't it work for a chassis holding a big transformer?
Edits: 03/31/15
UncleStu,
Many thanks for elaborating.
DG
nt....I'm gone
Edits: 03/28/15 03/28/15
Digital players generate little heat, not like amps do. open covers on an amp certainly makes them run cooler.The plastic, particularly if polycarbonate is used, can also be self damping.
Plus the last thing you want is dust on the laser lens assembly....
I believe DG knows what he is doing....
Edits: 03/27/15 03/27/15
If you must take the cover off your amp to avoid excess heat, you have a shitty or malfunctioning amp.Don't know why you're writing about lasers and dust. What does damping the cover have to do with dust on the laser?
IF "DG" knows so much, he can take care of himself and doesn't need you butting in. Don't you have some crystals to cook or something?
Tom E
Edits: 03/27/15
Well, you certainly show your feathers. No matter.In my systems removing the covers have always improved the sound. A discussion of this including DG was held a while ago. This had to do with captured EMF fields. Removing the covers certainly reduces a lot of the EMF generated and captured by the chassis. Removing the covers for me, has always resulted in cleaner, more pristine highs, with the greater resultant ambience and three dimensionality. OF course different set ups may differ in results.
And nothing was mentioned about excess heat. You inserted that. I happen to like to run my gear as cool as possible.
As for dust on the lens, enough dust and it doesn't matter if the machine has a damped cover or not. To my thinking, a certain amount of practicality rears its head.
As for the photo I doubt if it is a current photo. No brass screws, for example...
But I do not prowl the net trying to point out seeming contradictions. IT does not really help the advancement of audio.
But nuff said...
If you're going to insert comments though, please get them correct. I have NEVER advocated cooking crystals, LOL!!!!!
Edits: 03/27/15 03/27/15
I guess I've been insulted. I have no idea what "show your feathers" means.
You mentioned heat first. Read your own post. Are you aware that there is a certain optimum temperature range in which most equipment is designed to operate, and that temperature is probably established with covers in place (for obvious reasons)? This is nothing like removing the grilles of your speakers. A properly designed amplifier should incorporate heat management that allows for removal of excess heat. The only possible benefit is a slight extending of the already long life span of electrolytic caps. If your amp is so marginal that you need to cool it, perhaps you need a new amp.
Now you change your story and make a claim about the chassis generating EMF. Ooooh, EMF, the invisible, unquantifiable bogeyman of every shuckster sales pitch and audio paranoid. I think you have heard so much of this manufacturer's marketing malarkey that now you regurgitate it and believe it yourself. Please tell us how a chassis, other than the transformer which can be easily managed, emits EMF and how removing the covers of equipment reduces any kind of radiated interference? Most interference comes from OUTSIDE, and a metal enclosure on all sides is the best way to block it.
But if your equipment sounds better with the covers off, that's great. I won't argue that point for a second. You don't need to justify it with pseudo-scientific gobbledygook about why you think something might have an effect on the sound. I find it difficult to tolerate posting "facts" about why something you perceive is happening and thereby misleading other people who might read this forum and believe what they read here.
If anyone who doesn't know better is paying attention, DO NOT remove the covers of your equipment while it is in use. Exposing line voltage components or delicate parts can be dangerous. Most radiation and vibration comes from outside the equipment, and effort should be put into properly shielding it from both. If you want to do something, unplug it and securely attach a flameproof material to damp the top and bottom of the enclosure from vibration, which will probably have a positive effect on the sound after you put the cover on and then plug it in again.
And how did dust become part of this? I mentioned damping the cover of my CD player. What does that have to do with dust on the lens? I think lack of reading comprehension rears its head here more than practicality.
Why did you get into this at all? I made a comment about one piece of "DG" equipment without a cover and one with a plastic cover that might vibrate. "DG" spends a lot of time eliminating vibration from his system, with which I mostly agree, and posting positive results here. I saw that as a contradiction and wondered how he might reconcile it. It had nothing to do with you. I suggest again that you butt out unless you have something positive to offer, but of course you can post whatever condescending crap you like. Nobody is prowling, but you're certainly interfering.
I don't know how you're advancing audio by laughing at posters here. I guess they're taken seriously only if they accept your self-serving, pointless conjecture about why some things make a difference in what we hear, or what we think we hear.
And I really don't care whether you cook your magic rocks or sleep with them under your pillow or wrap them in Teflon tape or dip them in soft cheese. Notice I don't ever comment on your many threads on the subject. And I didn't write anything about that brass screw driver-mounting business, although I was tempted. You can believe what you want to believe, and anyone can follow your advice if it does not pose a threat to their safety.
Tom E
Showing your feathers= Showing your stuff.
There are often many reasons beyond a single aspect of sound which has to be factored in with modifications. That I saw some alternate reasons, I believe is a factor to be considered, whether or not you consider it important ( it is to me)
It is a well established fact that any AC signal ( read signal or even AC power) generates an EM field. Standard physics from the 1800's support this principle known as Faraday's law.
At this point, i can see any further attempts at elucidation would be wasted, unfortunately, so I will voluntarily terminate any further discussion with you
Peace
Yes, I agree that AC in a wire results in an EM field around the wire. How does that tell us that removing the cover from your equipment has some positive effect on EMI? Like Madisound said, if anything, the chassis is a sort of (not very good usually) shield. As a shield, it works both ways, keeping EMI emitted by the circuit inside the chassis and also blocking EMI from without. Do you posit that in this case, removal of a modestly effective EMI shield is why your gear sounds best with no cover? (I too have observed this phenomenon, by the way, but I don't pretend to be able to explain it. I think it is more likely due to eliminating some chassis resonance, but I really don't know. You'd think that a tightly covered chassis with a dampening weight on top would be less resonant than an open chassis, which is also more flexible because of the absence of the cover.)
For this reason all Audio Research Reference line of components have plastic perforated top covers. I heard from the dealer that its' not cost cutting measure but it just sounds better than metal covers .
Edits: 04/02/15
Ahhhhh, bout 9 years ago I fabricated some 1/4 inch polycarbonate top covers for a wealthy customer, but his amp ( Ref 300) went kaput and he had to send it back as I was too ill to work on it.Even drilled the top vent holes to spell his name, which pleased him immensely.
Oh Yeah Stan Klyne has plexi covers standard for all his preamps, including his phono units. Back in the early 80's me made a few to show case his workmanship for dealers. IT did that beautifully, but it also sounded way better, so it became standard
Edits: 04/02/15
Actually removing covers removes the cover running parallel to the PCB. It forms a giant low level capacitor rolling off the top end.
If you ca find it, read the Counterpoint white paper about why they copper plated their chassis ( both tubes and hybrid designs).The spurious magnetic fields all create surface "eddy currents". The plain steel has high resistance, the copper speeds up those currents.
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