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

my method of speaker toe-in and rear slant, thus inward and upward directivity, is part of why I don’t seem to get vibrations on the surface of the LP between/behind the sealed boxes I think. Your setup may be part of the solution, or .......

 

 

My SUT to select which arm and impedance or PASS for MM just fits under the side of my TT, (normally I can see/move it’s two selector knobs, shown pushed too far underneath the TT here) I have to move my Preamp/Amp cabinet to work on it. Notice felt squares on the end of the dust cover

Big Felt Squares so I can place the cover on it’s end when off for play

It’s big, you need to plan for where it goes during play, some covers would be huge, it may determine where you place other equipment, it did in my setup.

Some more felt on the face of the Reel to Reel Tape Player protects the cover when using the TT. Below, prior setup, SUT was on a shelf below the TT, actually harder to see the various markings, hard to position, but better now.

 

I can only comment on the original post in regard to on or off with dust covers…..

That Thorens engineer was covering up (literally) the original design problem with that model of deck…..

Which manufacturer would not allow a tolerance for eccentric records in the first design stage. Even worse not to address issues before mass production?

 

Thorens dropped a clanger here all right, big time and gave a stupid excuse!

 

Even stranger for a hi-end dealer to accept this and to finish the tale…believe the manufacturer that it was not ‘their fault’ 

Related:

Warps get helped, but for typical LPs, all that I play:

I definitely want to use something at the center spindle to assist rigidity, minimize air pocket bulge below, eliminate potential of any movement, i.e. LP firmly in place to transmit groove info most completely to the stylus, the forces involved are tremendous.

Sturdy designs like former Thorens TD124, Technics SP-15, current JVC TT81, I use somewhat heavy AT Disc Stabilizer, 300 grams

Clamps, and Retainers exist to reduce weight concerns for some designs, Ask your maker

Luxman PD441, 444, 555 all have a special ’load reducing’ motor design, magnetics reduce 80% of the weight on the bearing, so I got my friend rubber retainers used to hold tape reels on spindles the same diameter, you just push them on.

 

I like the idea of vacuum hold, but not the idea of a running motor, so I wanted to also use weight at the perimeter, I tried Wayne’s Perimeter Ring, unsuccessfully as the ring’s weights hang down too low and touch the wide rim of the JVC TT81

Here it is shown upside down, with the centering jig you need

My Mitsubishi LT-5V Vertical TT has a very ingenious hinged arm with spring assisted center clamp/pull to release

 

In my garage/shop, to keep an 8 track and fit a dual cassette deck in the stack, I changed to a Sony Front Loading Drawer Type TT, too light of a mechanism for a weight, and no clearance to place anything on/off anyway.

 

I found an advanced stylus P Mount, and then an adapter to convert P mount to 1/2" standard.

I believe the previous post is hi-jacking this debate.

I thought we were talking about turntables cover on or off?

 

Anyway, back on track please…..

 

oldaudiophile, you are a kindred spirit. I believe entirely what you say. I replied to the original poster without reading all through the other replies. I did not ‘hack’ your opinions but we are of the same old school l believe. Yes Thorens did a public relations job on that complaint about the cover being too small and unfit for purpose.

 

l am in the UK and Thorens dominated mainland Europe in the 70s and 80s (not UK which was Garrard territory). I am very familiar with Thorens turntable owners in that period and spent many evenings music listening with their set ups. I can never recall any manuals stating remove the covers ever! Unless someone bought a chassis deck to install on a hi-fi bench then the cover on or off issue may have been different.

Hi-fi has become a bit of a home living statement now so it must be always on show. Now it’s all about design over aesthetics and manufacturers today have abandoned in most cases the use of turntable covers.