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.

billstevenson

"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.

@wyoboy 

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.

What I do have is one of those acrylic mats you can buy on Amazon for $20. In the end I really only need to keep dust off the platter itself. For the rest of the table a feather duster and/or microfiber cloth now and then work great.

This photo shows that acrylic mat on the platter. I just remove it when I play records.

@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