Some thoughts on dust covers
Over the course of time there have been many discussions concerning the subject of dust covers. They tend to revolve around the central question: Should the dust cover be down or up while playing records? Some of these discussions have been nasty, consequently I have refrained from participation. It is hoped that I can provide some common sense that was given to me by someone of unquestioned authority many years ago. During college and after, from 1970 to ~1980 I worked in HiFi retail, selling high end lines of audio equipment. One of these lines was Thorens. Sometime around 1977 or 1978, if memory serves, Thorens introduced their new TD126, as a top of the line TT with their own arm and I sold the first one at our store to very good customer. He came back very unhappy after the first night of frustration with it. The problem was that with the dust cover closed some of his favorite records were hitting tangentally on the very back were the platter came closest to the dust cover when it was in the closed position. I called the manufacturer's rep and he set up a three cornered phone call with himself, the Chief Engineer of Thorens at the time, and me. I don't recall the man's name, but it doesn't matter, it is what he said that matters, then and now. The Chief Engineer explained that the problem was caused because the hole in the offending records was slightly off center so there was an eccentricity as such a record rotates about the spindle. The solution was simplicity itself, the dust cover should be removed always when playing records. That the intent of the cover is to protect the turntable when not in use. I pointed out that we lived in a semi-arrid environment (San Diego, CA) which is dusty to which he replied that if the environment was too dusty for records it should also be considered unhealthy for people to be breathing the air. He recommended are filtration, not dust covers to address environmental concerns. The rep asked about air bourne feedback from speakers and the Thorens guy laughed and said that if that was a problem in a given system, relying of the dust cover was a very flimsy and ineffective solution and that proper measures should be instituted to provide meaningful distance and isolation to ameliorate the problem. So the often offered extremes: a) Always play your records with the dust cover down, or b) put the dust cover away in it's box and never use it, should both be recognized for what they are are - not solutions at all. First principles: Identify the problem(s), seek solutions and alternatives, prioritize.
Am l am correct in thinking that Rega and Project turntables are light weight minimalist designs? They certainly look like featherweights in the hi-fi boxing ring…. Maybe that’s why they shy off covers? Highly likely they already know that their design structures are not massive enough to resist external forces unlike decks with heavier more substantial plinths.
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I have two turntables, and I like both. A Sonograph SG-3 and a Kenwood. Both have dust covers that I use to protect the TT when not in use. I had noticed the acrylic dustcover material would attract dust to the cover and would sift through the crevices in the dustcover hinge joints. I ended up solving this by getting a destat source from Amstat Industries to produce a charge to counter the electrostatic attraction of the Acrylic. It is a polonium 210 alpha emitter fixed in a bar array, and gets two sided taped to the inside of the dust cover or base of the TT. Works well; is safe. Not inexpensive because it needs to be periodically replaced as it decays off and looses its effectiveness. but it does destat the dust cover and everything under it including the vinyl record. |
I haven't seen it addressed so far in this discussion so I'll relate an experience I had back in the late 60s / early 70s when visiting my favorite audio emporium. The owner kept a very orderly showroom and a regular dusting of the display components helped keep it that way. On one visit, the owner took me aside to show me a discovery he accidently made while on his dusting routine. If memory serves, I believe the turntable in question was a DUAL 1019 and the cartridge was a SHURE V-15. He played a record with the dustcover down, ran his dusting cloth over the plastic lid and the playback sound changed considerably. He then produced a "ZeroStat", a pistol-shaped device that was used to de-magnetize vinyl reccords prior to playing and activated it over the dustcover. The playback sound returned to its previous character. If I hadn't seen and heard it I wouldn't have believed it possible ! The dusting cloth had magnetized the dust cover enough to cause the tonearm to lighten up its tracking force and the ZeroStat dispersed the magnetic field to restore it to its original tracking force ! I never tried to duplicate the feat at home and had no reason to believe that the owner was playing a trick on me, so, to this day, I play my TT with no dustcover in place. Was he trying to get me to buy a ZeroStat ? I dunno, but I did buy one and still use it on occasion ! |
The zerostat works, but what it does is to reduce static charge, not magnetism. Static charge develops on every LP when it is handled because vinyl is one of several materials that easily accumulates an excess of negative ions on its surface. The magnitude of the negative charge can be great enough to dramatically attract the cartridge, increasing the effective vertical tracking force of the stylus on the LP, causing distortion and even damage. This of course is a pull on the cartridge in the opposite direction from what you observed with a lucite dust cover that got charged up and then discharged. In that case, the charged cover was exerting an upward force on the cartridge. LPs get charged up when you remove them from a paper sleeve or when you touch them with your finger tips after walking across a wool carpet, for examples. |
mylogic I’ve witnessed Arlo Guthrie a few times yapping away, then he says "I know I’m supposed to be singing, but you can’t always do what you’re supposed to do’ And the stories are all related to where he started. You would love a Buckminster Fuller lecture, in 1967 that crazy man took an entire auditorium at Pratt Institute on a meandering thought trip and at the end of the hour slammed it home, OMG, I still remember it like it was last week. Vibrations getting to the surface are all related to the Dust Cover on/off issue, as is this fundamental question about equipment location. https://forum.audiogon.com/discussions/location-of-compoments?lastpage=true&page=2#2757920 Thorens, yeah, they should have had more clearance than that in that model.
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elliottbnewcombjr ‘’Alices Restaurant’’ has all come back to memory! Buckminster Fuller is new ground and has made me look into his history…..’’Spaceship Earth’’ and all that! One of his theories remind me of Linn’s LP12. All the expensive tinkering over the years and upgrades to make this model better and things have not changed in 50 years. l love his logic and this quote from him…. You never change things by fighting the existing reality. To change something, build a new model that makes the existing model obsolete. Why have Linn never built another turntable and try to better the LP12?
l wonder what Fuller would have made of this staying in the past?
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lewn So pleased you are following this very interesting thread, some call it a boring subject….you know! The last few posts are relevant to dust covers, you were just not paying attention but just wanted to reciprocate. elliottnewcombjr was just stating the obvious with ongoing engineering development. Buckminster Fuller was a renown inventor and his views are also relevant to the discussion.See his famous quote posted.
In an earlier post elliottbnewcombjr also stated this opinion on turntable covers…. ’’Impractable TT’s (any TT) without a dust cover is an incomplete solution, an abomination, they should be ashamed of themselves’’ Fullers reasoning is the same…. ‘’You never change things by fighting the existing reality. To change something (that can be improved) build a new model that makes the existing model obsolete’’ Elliott and myself may not agree on everything, but we do agree with Buckminster Fuller and the need for constant development.
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I guess that is "yourlogic". Unfortunately or fortunately, we are not all living in Fuller's geodesic domes. Another prediction of his gone awry. But it interests me that you can read what Elliot wrote about dustcovers vis a vis turntables and in any way conform that thought with Buckminster Fuller's thoughts on anything. The only way I can see that parallel is if you take the dust cover as a modern innovation, which of course it is very much not. Far from it. It is rather more accurate to say that progress in turntable development has included the gradual elimination of dust covers. |
I thought you made your position clear in your first post, no need to say any more! You are right - electrostatic forces are orders of magnitude more powerful than gravity. Another way to create static charges is to rub vinyl with a diamond stylus. Those charges immediately attract dust. Interestingly about 30% of dust extracted from records is diamond! In my opinion the OP raised a good question - should the dustcover be raised or not when playing a record. Clearly this presupposes there is a dustcover and that it is hinged. If your turntable does not have a dustcover, or the dustcover must be removed when playing, this topic is not going to change anything for you. I read up about the Wilson Benesh GMT One System turntable, which weighs almost half a ton and uses lots of materials science, university types and research grant money to minimise unwanted resonances. This behemoth does not have a cover, although it costs house-money! Obviouly they don’t worry about airborne feedback, or dust! For the record (sic) my dust cover is hinged to an outer plinth which only connects to an inner plinth via the sandstone blocks they stand on. Otherwise there is an air gap, a bit like a double-glazed window. |
Stylus rubbing on vinyl is not a cause of static charge. This was shown by Shure Corporation in their published white paper on static charge. I and some other guy here who also owns a static charge meter have repeated the experiment with the same result. No cigar on that idea. My position has been stated twice already. I use no dust cover during play; I completely remove the cover, if the TT has one. But I advocate that each of us should make his or her own decision. My practice is based on my listening tests and my subjective opinion of what sound best. I do agree it’s a fine idea to cover the TT when it’s not in use. For the past many years I’ve had 5 TTs up and running with 6 different tonearms and cartridges, 3 TT s feeding one system and two TTs feeding another separate system. |
@lewn Thanks for that Shure thing! I guess it is in a chapter from 1978 in high-fidelity-phonograph-cartridge-technical-seminar-faq.pdf entitled CHARGES ON THE RECORD--A STUDY OF STATIC ELECTRTCITY ON PHONOGRAPH RECORDS. The only mention of stylus rubbing causing electrostatic charges seems to be "Incidentally, measurements with these instruments will also show that electrification from the direct friction between the diamond and vinyl is, oddly enough, negligible’. The author created static charges initially by rubbing the record surface with cat fur (labelled CAR FUR in the table!) resulting in 30,000 Volts when the record was lifted from the table. Considering he switched cat fur for a more repeatable 10,000 volt probe, I am not surprised the stylus is regarded as a negligible (but not zero) contributor! The seminar reinforced that the most effective way to temporarily remove static is to use a carbon-fibre brush. One was attached to the V15 Type IV cartridge but this approach seems to have gone the way of the dodo. Saved me spending on a Zerostat! Another surprise for me was learning just how much static electrical forces can change the tracking force! All good stuff ... |
In my informal "experiment", I first yanked an LP from its paper sleeve (in order to be sure it got charged up) and measured the charge on one surface, 11kV. Then I treated that surface with my 40 year old zerostat and measured the same area again, 0.1kV. Then I played the LP and measured the same area yet again, 0.2kV. That is the definition of "negligible". And the very small increase in charge density may well have been due only to my handling of the LP after playing it. However, you are not alone in your previous belief that the diamond stylus rubbing on vinyl causes static charge. Several makers of the very expensive static charge removal devices (not the relatively cheap Zerostat) parrot this belief in their advertising brochures. |
It seems the 30,000 Volts recorded by Shure corresponds to the breakdown voltage of air in a Californian winter - with a very low relative humidity of 10%. Shure's measured voltage dropped dramatically when the record was placed on the grounded platter (much of the field migrated to the platter side) and returned as soon as the record was lifted. Prima facie it seems that when you played your record, it doubled the charge so I am keeping an open mind on whether the rubbing stylus can create charges. Charges attract dust like crazy, and dust down to smoke-size particles and even down to a few microns may be significant. If I remember, I now run my carbon-fibre brush both before and after playing to try to remove fresh dust before the records goes back into its anti-static sleeve. I am still waiting for an ultrasonic cleaner to arrive from China! In modern physics theory, electromagnetic and gravitational forces have hugely different magnitudes. About 1,000,000,000,000,000,000,000,000,000,000,000,000 times different! Which explains how plastic combs can pick up paper on a dry day, and charged records can significantly affect stylus tracking forces. That Shure seminar was not too keen on Zerostat-like devices: "Another form of active ionizer is in the form of a pistol-shaped, device, which produces positive ions when the trigger is pulled, and negative ions when the trigger is released. This device is effective for large charges, but it is hard to avoid leaving residual charges on the record since there is no way of detecting the zero charge condition" which accords with your measurement. |
"Prima facie it seems that when you played your record, it doubled the charge" First, 0.1kV to 0.2kV is a range where the meter is not very accurate and readings are not very repeatable. The meter never reads zero, for example. So the difference between the two readings may not even be statistically significant. Second, like I said, it is much more likely that my touching the LP had more to do with the difference, if it was even real. Third, such a low amount of static charge is inconsequential even if real. The problem we are addressing has to do with charges far in excess of 100V (0.1kV). 10kV (or 11kV in the specific case I noted) is 100 times higher 0.1kV. Do you have a background in this field, or are you a physicist or other scientist? If so, feel free to point out the error in my thinking. Since you don't have access to my meter, you could not have known its quirks, so I don't mean to criticize you for that. I don't know why you compare "electromagnetic force" to gravity. First, the magnitude of the difference as you express it has no meaning unless you know the relevant parameters for the source of the EM force, in the case of EM, and the sizes of the objects that experience gravitational attraction and the distance between them, in the case of gravity. But also, electrostatic attraction is not identical to electromagnetism. The point about the Zerostat is only that if used properly it will reduce the charge to a harmless level. And it costs a lot less than most of the modern alternative gadgets. Some flat earthers maintain that what we experience as gravity is due to electrostatic attraction. They have to resort to such an explanation, because if the earth were flat, it would not be massive enough to account for the gravity we do experience. |
@lewm I don't know why you keep posting on this either--you've covered it soup to nuts and, at this point, you won't change anyone else's mind who disagrees. @dwette Having a custom cover made of acrylic to protect the TT is not expensive--i had one made for my custom Jean Nantais table for $120. I remove it when i play but i have a second TT, an old Sony DD from the 70's that has a hinged dust cover that i just put up when i play LPs and have both removed it and played LPs with it down and i can't tell the difference in any position, although i would probably unhinge it and remove it if that were convenient when i play LPs. |
I don't need a dustcover, nor do I even want a dustcover. Whether it's $120 or $350 it won't make a difference for anything anyway, IMO. But as I mentioned earlier it's also impractical for me. There is really no way I can site one on my turntable that would make any sense and not become a total PITA. This photo shows that acrylic mat on the platter. I just remove it when I play records.
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@dwette I was going to ask for a pic of your TT but you attached one and i can see there's no way for you to fabricate a cover so that's that. Seems like a bit of PITA to have to feather dust and mocrofiber everything but since playing LPs is tactile anyway then i guess that's just another part of the process...in our environment here in Arizona we have so much dust it would take much more than that to clean the table if i didn't have a cover so i'm glad i do--and it's a simple matter to just take it off and set it to the side when i play LPs... |
@dwette BTW how did you attach the pic of your TT--i tried to do that in another thread and it was just stripped by AG |
Using a feather duster on occasion isn't a PITA at all. It literally takes less than a minute every once in a while. Managing a big acrylic dustcover most certainly is a PITA. I previously had a Clearaudio Ovation with a single 9" arm, and had an acrylic cover made for it. It ended up a stupid waste of money because I got too lazy about using it and had no good spot to store it while playing records. Good riddance to the whole unnecessary dustcover nonsense. That's where I am on it. I really have no issues having none at all. |
Wyoboy, I feel compelled to correct incorrect information that falls within my range of knowledge. Ideally, the information on this site should be as accurate as possible, because some of these posts are read and believed by newcomers to the hobby. For example, that is why I posted to correct RichardBrand’s statement that the stylus rubbing on vinyl causes static charge. You can call me a pedant or some other pejorative term because of my compulsion to be an intellectual policeman. Maybe I deserve it. I don’t claim to be infallible, and I always welcome correction; I have certainly been wrong many times; I only know that because others have seen fit to correct me. But that way, I learn too. The question for me is why do you care whether or not I post here? dwette. I too use lucite (acrylic) dust covers that just cover the platter surface, like yours, on my Technics SP10 Mk3 and on my Denon DP80. My Kenwood L07D was sold new with exactly that type of cover, and I use the original Kenwood version on my own L07D. I need two more, one for my Victor TT101 and one for my Lenco. They are in my basement system. For some reason, the finished room area in my basement is amazingly dust free, maybe because the few windows down there are sealed shut. |
I must confess that I was educated in physics at Cambridge and I have tried to keep up since! Physicists now explain almost every known property of the universe in terms of four fundamental forces which act on the very smallest particles, including the electron. Protons and neutrons comprise three smaller quarks! These are the objects for the comparison of the four forces. Gravity and electromagnetism both operate over long distances up to infinity and follow the inverse square law. The word electromagnetism is used because a moving charge creates a magnetic field. The other two forces only operate over tiny distances about the size of an atomic nucleus. In everyday life, we experience gravity as a dominant force, but that is because every atom in the earth tugs at us. These same atoms have no net electrical charge, so the way-stronger electromagnetic force balances out as equal attraction and repulsion. But rub a few electrons on to an insulating surface and they will lift paper and cartridges against all the gravity of the earth. They will also attract and hold dust. This is the principle used in electrostatic air filters, which my electrostatic speakers would try to emulate except for the built-in dust covers (back on topic?).
You did not do a very convincing job because your own measurements indicated the opposite. The "white paper" you mentioned inferred the contribution was negligible (not zero!) compared to 30,000-Volts produced using cat fur! Mind you, that seminar was spruiking the benefits of the static-reducing in-built brush Shure introduced with the type IV cartridge. I contend that any static will encourage dust collection and that is bad for record playback. I am not silly enough to think your measurements were accurate, since you only stated results and not the procedure used to get them. Hence I wrote prima facie or on the face of it! The most reliable way of reducing static is to immerse your record in a conductive medium, like water, but then you have to dry it without re-introducing static. More contentiously, I believe the best way to reduce the dust load on your records is to use a hinged dustcover, but only if you have one. Operationally it is not too hard - bit like lifting the lid on a toilet. Unlike a hinged dustcover, leave the lid up when in use ... |
This is what Google’s generative AI says in response to "can record stylus cause static"!
I agree with all of this, except that getting a final zero-charge out of a Zerostat is hard - as pointed out by Shure. Also no great surprise that Shure, as the then dominant maker of stylii, did not highlight that they cause static. |
The human body is normally a great drain for static. Rubbing paper against a record creates static, handling it is more likely to drain some away especially if you only touch the edges and the label. My TAS-recommended AudioQuest carbon fibre brush explicitly relies on the user to drain the static to earth, via a metal handle that contacts the fibres. The human body is also a great source of dust, shedding its outer skin roughly every three weeks. Maybe your electrostatic loudspeakers are acting as electrostatic dust filters for your basement?
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Since when are we taking anything Google's generative AI has to offer as an authority? Frankly lewm's reference to the published work of Shure years ago is an established, credible resource and those who disparage it must be doing so only because they have not taken the time to read it. Shure's published work has always been of the highest order and commands the respect of the entire industry. This is not a fly by night outfit only out for the fast buck. Google on the other hand...give me a break. After we get done talking dust covers to death, if anybody is left standing let's talk about the good old Dust Bug! :-) |
Dear RB, Googles AI is full of.... baloney as regards bullet number one, and the whole business of AI is scary, because we tend to believe ""AI" and AI is nothing but a computer that scanned a bunch of opinions put into print by humans, and humans are still faulty. Shure did the actual experiment. I repeated it and so too did another person who regularly posts here. He and I got actual results that agree with the Shure publication.But like I said, do whatever you want. "The human body is normally a great drain for static." Where do you get that? Static charge is nothing more than an imbalance of positive vs negative ions sitting on the surface of an object. In other words, it's a phenomenon of surfaces. So it is probable that if your body is charged up, because for example you are wearing leather soled shoes and you walked across a wool carpet before touching your LP, you might charge up your LP the instant you touch it. (Let's say your surface becomes negatively charged and touching the LP pulls positive ions off the vinyl surface to neutralize your own body surface, leaving negative charge on the vinyl. Vinyl is near the bottom of the triboelectric table [see for example the article on the triboelectric series on Wiki] and dry skin is at the top. This means skin "wants" to give off charge to vinyl. There is much that is unknown about the electrostatic charge phenomenon, and the triboelectric series and table are only crutches.) Your "TAS-recommended" AudioQuest carbon fiber brush is nice but far far from a perfect guarantee of a charge-free LP; I own one and use it before every play while grounding myself. It does not work all that well to prevent static charge build up, which in the case of vinyl is an excess of negative ions on the surface of the LP. Of course, pulling an LP out of its paper sleeve is another important cause of the static charge on LPs, as I mentioned 3-4 posts ago; it's what I did to create a positive control for my experiment to see whether the zerostat worked and whether the stylus tracing the LP is a cause of static charge, trying to repeat the Shure experiment. The speakers in my basement are Beveridge 2SWs. You can categorize them as "electrostatic" but in fact they are a unique design in that there is no charge on the membranes in the resting state. There is no external high voltage bias supply as for every other ESL. So, no dice. On the other hand, the Sound Lab 845PXs in my living room are conventional ESLs, and yes there you have to be wary of their collecting dust on the diaphragm. "Shredded skin" does not strike me as an important cause, if it is any cause at all, of dust, unless you keep 30-40 people in your listening room. Maybe you were trying to be funny. |
Can't trust reviews or media - the GMT has a very nice integrated hinged dust cover. Ideal for those who can't afford hepafiltration systems for their home/living room.
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I did take the trouble to find and read thoroughly the Shure seminar articles. Have you read them? There is absolutely nothing about styli causing static except that throwaway line that it is negligible. No experiment, no discussion, no measurement, nothing. Generative AI uses large language models to make inferences. Most likely Google's includes everything you have written on the web, and weighs it against what everybody else has written. I find it both credible and fascinating. My dust bug has gone missing, but the base is still stuck to my Garrard 301. I recall it quite audibly played what was coming up on the record, but have no idea why they fell out of favour. |
I have a Rega P6 with a dust cover. I have always used it with the cover up for no particular reason. Convenience maybe. Reading these posts I went up to do an experiment to see if I hear a difference. I was gonna try cover up, cover down and cover off the plinth with my best quality records. I dropped the needle and NO LEFT CHANNEL! Turns out the amp picked that day to crap out. It's under warranty so I'm sending it off to Focal Naim for repair. I'm still gonna do the experiment but it's going to be awhile. I doubt my set up is detailed enough to hear a difference. |
So you did not really trust the Shure ’white paper’ you quoted to support your erroneous assertion! That’s quite an admission from somebody who claims to want the information on this site to be as accurate as possible. According to your posts, you had a residual voltage of 100-Volts after Zerostat and 200-Volts after playing, but you have not stated what meter you used or its repeatability. This is what the Shure seminar actually published on methods to reduce static. My highlighting and [comment]
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Richard, please get over yourself. I did believe what Shure wrote because of who they were, a company with high integrity and a scientific approach that they adhered to by backing up the majority of their information with decent experiments and by reporting the data therefrom. Did you read the paper? I actually bought the meter not only to do the experiment but mainly to measure the charge on my ESL diaphragm in the first place. So since I already had the meter, I used it for the purpose described, with results described. If you doubt me, buy or borrow a meter and do it yourself. But don’t infer I’m a liar or that Shure corporation are unethical. I also have to ask what would be my motive to deliberately post false information here? It makes no difference to me whether the stylus does or doesn’t cause static charge. I think what’s going on here is that you hate being corrected. Believe me; no one cares. Other reasons I bought the meter. (1) it seemed like a cool thing to have, and the other guy on this forum who did the same experiment many times with the same results told me where to get it. I have a weakness for gadgets, and 2) I’m a scientist and insatiably curious.
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The ES force is determined by Coulomb’s law, which like Newton’s equation for the gravitational force is an inverse square law. Both forces are inversely related to the square of the distance between the two objects under consideration . The difference is that the ES force is directly proportional to the product of the two charge quantities, where gravity is directly proportional to the product of the two masses. So I couldn’t make sense of that flat statement. |
Have a look close to the end of this Wilson Benesch YouTube video on the GMT One System. The founder says they did design a dust cover, but when they added the transformer box above the tonearm pivot point, it no longer fitted! For what it is worth Most Technology and R&D Ever in a Turntable? Wilson Benesch Riveting Presentation - YouTube
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And you claim to be a scientist! Physics has moved on a bit since Newton and Coulomb as it tries to produce a unified model of all the known forces and their interaction with all the known particles. If you turn 'proportional' into an equation with a constant, the constant for the electromagnetic force is about 10**36 times bigger than the constant for gravity. Thats why a very few stray electrons (not ions) easily overpower the gravity of the earth, and why they attract charged bits of dust floating in the air. Why don't you believe that a natural insulator like diamond rubbing on vinyl creates charges in the same way that paper and cat fur can? Especially when your own measurements quoted here support that! |
@lewm I don't care if you keep posting on this subject or not--i've actually learned more from you about vinyl matters than most anyone else here except perhaps mijostyn. i was simply echoing your own words where you said "I don't know why I keep posting on this, because it is one of those questions where every one of us is already convinced of the efficacy and rightness of his or her current practice." And i didn't see anyone after that changing their mind despite your excellent advice. But didn't intend to make you stop so feel free to fire away. Happy New Year. |
RB, to the question contained in your last paragraph, my current opinion, open to change if presented with contrary data (not a “belief”), is based on my data, the testimony of another Forum member who’s done the experiment many times before me with his own meter, and on the Shure Corporation white paper. You can buy a decent ES meter on eBay for less than $200. Why don’t you buy a meter, make some measurements, and then we can discuss. Don’t come to me with “Google AI” and no actual data or a reference to someone else’s actual data that is publicly available. The concept that the diamond on vinyl causes static charge is repeated over and over again in advertising for anti static devices, in audio forums like this one, etc. So it does not surprise me that Google AI believes it. I insulted you earlier,so I’ll forgive you for insulting me. If you want to go into detail about ES force vs gravity force, probably that would bore everyone else. But it’s not relevant. Wyoboy, sorry I over-reacted. |
Yes I read the Shure papers. You are right there is no data to back up their assertion. I don't know what happened to my Dust Bug either. Maybe it generated so much static charge that it self repelled into the dust bin? (Just kidding) Pity because it definitely appealed to me as a good idea back around 1969 or there abouts. Certainly an option for the dust cover-less. As I recall at that time I was struggling with an AR turntable. Horrible thing. Hated the arm. The dust cover for it got deep sixed very quickly. And Bob's your uncle, I bought a Dust Bug! Which worked a treat and stayed with me through a succession of turntables. I wouldn't be surprised if it is still in service on my old TD-125 somewhere. But let's think this through together. The footprint of a Dust Bug is considerably greater than the contact area of even the worst case conical stylus. If the Dust Bug did not generate significant static charge, and I posit that to be so, then it is reasonable to deduce that a stylus tracking the record grooves should certainly be even less. And without the means to measure the actual number, as reasonable people we can accept Shure's assessment that the amount of static generated by a stylus on a vinyl record, while somewhat above zero, it is negligible for all practical purposes. |
I can't resist. Too much idle time. The equations of Newton and Coulomb are quite adequate for considering the situation at hand. You used their constants yourself as a basis for your statement about the relative magnitude of the two forces. No need for a unified theory here, which anyway does not exist. The reasons that your blanket statement about the relative strengths of gravity and electrostatic charge does not hold water are at least two-fold: (1) The units of the gravitational constant and Coulomb's constant are different. You cannot just assume that a numerical ratio between two different quantities is meaningful without considering the units (apples and oranges), and (2) in one case the objects are considered only for their mass (Newton) and in the other case the objects are considered only for their charge (Coulomb). I would say yes, in some cases the ES force can be greater than the gravitational force. In other cases, no, gravity dominates. It depends upon mass vs charge. One other difference between gravity and the ES force is that gravity is generally a force of attraction between two objects, whereas the ES force can be a force of repulsion, when the charges are alike in polarity, or attraction, when the charges are opposite in polarity. (Yes, I know about the question of whether the reason the universe is expanding means there is a repulsive form of gravity caused by dark matter, etc. But that is not an earthly problem.) |
My-O-My ! I never expected to kick up so much "dust" with my re-telling of the story of when my audio dealer dusted his turntable dust cover and created enough magnetism to alter the stylus force ! Perhaps we can end it all simply by turning our attention to another interesting thing I noticed on my 1920's Victor "Credenza". On the lowest portion of the rather sizeable and heavy lid is a decal that states, "Close Lid Whilst Playing". Since it was effectively the turntable dust cover, I hope to stay within the confines of the original post. There definitely is a difference in the quality of sound when following the directions though I've never decided whether it was a diminution of the very noticeable stylus "scratch" or a real enhancement of the sound as a result of confining the sound box to a more restrictive acoustic. Victor even encouraged the regimen of closing the lid by providing the lid with two "dashpots" which damp the lid closure enough to prevent any slamming effect. On the Columbia "360" record player from the 1950's, the edges of the lid were lined with felt so that when the lid was closed it definitely created a different acoustic situation in which the cartridge had to function. The Speakers were located on the opposite sides of the unit and one driver was purposely wired "out of phase" to create a diffusive effect. Later models of the "360", though much more modern in the cabinet design, went even more deeply into the idea of encapsulating the cartridge in its own acoustic by integrating a fully sealed plastic container within the player to isolate the cartridge even more fully than the original model. You almost have to pry the lid to open it ! My question is : Were there any modern turntables that had a dust cover/lid that was designed purposely to be closed during the play cycle to take advantage [?] of the difference between an open or closed acoustic surrounding the cartridge ? Some of us have certainly experienced acoustic feedback when positioning a loudspeaker too close to a sensitive turntable that created an acoustic feedback through the cartridge, so the reasoning follows that attention to the acoustic in which a cartridge must function is important. I own both an early and late Columbia "360" machine and there are mono records that sound like fine stereo recordings on these machines ! Amazing !! The outer lids on both the Victrola and the Columbia "360' machines were of wood so they could not be magnetized. Thoughts ? Experiences ? |
I think the easy way out of this impasse and high blood pressure is….
Cover or lid, which ever way you want to play it….. ———————-
1. If the thoughts of dust filling your groove ruins your musical enjoyment, and have a lid…keep the lid down. 2. If you are worried that the sound will be compromised with the lid down or know it will be, as Arnie would say….’Don’t dooo iit! 3. If your hi-fi sounds great to your ears, you are happy with listening to music and you don’t notice a difference up or down….and have a lid, stick it down and save a lot of additional cleaning! 4. If you have a turntable without a lid, content or enjoy sometimes a little dusting fore play each time you want to listen….stick to a turntable without a lid! I think l have about covered it? That’s my Logic
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I'm not qualified to speak on static, but dust I do know about, especially with respect to inhaling it and the allergies it can cause. When you wrote, @lewm ,
I'm afraid you are wrong. The predominant, component of household dust is human skin, though I expect it has been shed rather than shredded. |
@lewm @dogberry According to this it's a "myth" that dust is mostly dead skin https://www.livescience.com/32337-is-house-dust-mostly-dead-skin.html Couldn't read the Canadian dust study w/o a subscription... FWIW |
Googled "what is the composition of dust". Found this on the Martha Stewart page: "But there is one important myth to bust: While dead skin cells certainly do make up part of the dust in our homes, it's not as big of a portion as you may think. Sean Parry of Neat Services notes that people often assume that more than 50 percent of dust comes from dead skin, but in reality, "most of that is carried away by water when we bathe, ending up not on our floors, but in our sewers." ' I have no dog in the fight. I am a dusty nihilist. |
DUST and all that! Yes there is so much on the internet about dust! Most comments on here and debates describe the problems of household air contamination. Within the original post the hi-fi element of turntable covers was the question…dust or sound constraints! One thing that there has been no real quantitative answer to is, what is the shed skin % Shed skin may not be a big percentage overall but it would certainly be one of the highest individual components. Perhaps one other high pollutant should be an added element to the debate controversial or not…. Smoking could be the biggest additional problem as by smoking habitually, intentionally (or not) adds to the mix arguably the worst pollutants of all into the living environment. Various dangerous chemical particulates and sticky nicotine just love records, electrical equipment and other clean surfaces. If you have ever had to redecorate a house of a chain smoker the evidence is there as old nicotine burns right through a first coat. I know lots of people who advertise books, records or equipment are quick to emphasise that they come from a smoke /pet free environment.
Does any authority on the subject have a scientific breakdown as to approximately what percentages of household airborne components normally contain? |
