Dealing with Static on LP palyback

@lewm 

I did not know whether optical cartridges do their signal generating work inside the cartridge body (which would  mean they have the potential to generate EMI) or in the downstream amplifier

Current DS Audio optical cartridges contain three Light Emitting Diodes (LED).  One is there as a visual cue to the user that the cartridge is receiving DC power.  The other two LEDs emit constant infra-red which shines onto two photo-receptors. This is essentially the technology used in the fibre-optic cables so loved by audiophiles for galvanic isolation, but without the fibre.

The groove modulation is transferred to two shade plates which partially block the infra-red path, thereby causing the photo-receptors to create a nominal 70-mV AC signal at audio frequencies.  This is entirely analog - no nasty digital hash.

All other processing is done at a distance in a phono stage, which has to process position-dependent rather than velocity-dependent input.  There is nothing magnetic in the cartridge.and nothing to cause EMI,

then why don’t you buy an inexpensive ES charge meter and do the experiment with an optical cartridge? The prediction is that the optical cartridge would generate ES charge on the LP

My prediction is that any diamond stylus will generate electrostatic charges on any vinyl LP. If such a charge attracts a positively charged dust particle, the combination becomes electrically neutral.  No charge measuring device will detect a difference because there isn’t one.  However the dust particle will be effectively glued in place, causing a tick or pop when next played.  It can be removed in an ultrasonic cleaner by being ’blasted’ out, but is rarely dislodged by the stylus. The ticks are there every time the record is played, but can sometimes be removed by an ultrasonic clean.

the stylus/vinyl interaction does not cause accumulation of negative charge (insert reason here).  Neutralized charge is no longer charge at all

Oh, at the microscopic scale both the positive and negative charges are real and are still in place.  There is no net charge to be measured on the macro scale, but the incredible force of electrostatic attraction remains.  (I am glad that this time around you have not ridiculed the disparity between gravitational forces and electromagnetic forces - one of the greatest mysteries in modern physics)

You, however, do have a strong opinion that seems to withstand the barrage of facts

There are no relevant facts in the quoted Shure "White Paper" which is actually a handout prepared for a road show, as far as I can tell.  Even your own measurement goes in the wrong direction to support your claimed ’fact’.  I bothered to read the Shure stuff because your interpretation flew against the known physics, and it turned out the physics was upstanding.

The charge of a single electron is tiny, and the techniques used to first measure it using the Oil drop experiment - Wikipedia by Millikan and Fletcher are still taught in university experimental physics classes.  Millikan won a Nobel physics prize for this exacting work.

Your cheap charge meter stands as much chance of detecting a few electrons as eyeballing a record has of seeing micron-sized dust particles.  You need a scanning electron microscope for the latter!

Maybe a physics experiment using a needle probe just above the groove could react to the presence of a dislodged electron.  I doubt it, and you would need a full lab setup. To show whether the electron was dislodged by the stylus, you would need a probe before and after the stylus.  All that to show that the triboelectric effect is real!

Your explanation for why my meter measures no net charge increase on an LP surface and mine are different in phenomenology but not different in that the net result is no net increase in negative charge on the LP surface after playing a record.  Once again, it is only the results of my experiment that convince me.  You don't seem to realize that you need not give up your conviction that the stylus may give off electrons or negative ions to the LP surface.  I am allowing that maybe this happens, but for some reason the net charge on the surface remains neutral.  I offered one hypothesis to explain that, and you offered another.

You wrote, "Your cheap charge meter stands as much chance of detecting a few electrons as eyeballing a record has of seeing micron-sized dust particles.  You need a scanning electron microscope for the latter!" I cannot contend with such bullheadedness.  Where did I say I see electrons or that it is even possible to see them, even by the way under any electron microscope known to man? The meter measures electrostatic charge.  Electrostatic charge of the magnitude of a few or several thousand Volts is what we are worried about.  That much the meter can do easily and demonstrably does do. Once again, I do not and did not say that diamond does not give off electrons to vinyl; I say only that a resulting negative charge does not accumulate. Neither of us know why that is the case.

@richardbrand I have a Micro Seiki TT, with an external motor in a cast iron base, the TT itself is a 12 lb solid brass platter on a cast iron base.  The base and platter is grounded to earth.  The unit also has a vacuum system that sucks the record onto the brass platter, but unfortunately my ex-wife's cats clawed the gasket sealing material and that is no longer available.  Consequently, I use a TT mat.  I have several that I have used in the past - a thick Sorbathane that sticks to the record and platter, a white acrylic one currently in use, A thinner orange mat made of a soft rubbery substance, very much like Sorbathane but of a different brand.  They all produce static, except when the record was sucked onto the brass platter back when I had the vacuum in use.  

The belt that drives the platter is a single silk thread.  I do plan to upgrade to a different belt.  Silk does generate static for sure, but both ends are earth grounded - the platter and the spindle end.  I doubt the silk thread is a static problem.

I do have carpet in place, although I rarely notice static build up when walking on it and touching a doorknob.  It does happen occasionally, but rarely.  I'm not sure of the carpet material, but I'd bet it is a synthetic.  

@oldaudiophile I've looked for things in the past to make a dust cover.  My favorite idea was making one out of safety glass and using a fish tank type construction.  It was a great idea until I discovered what it would weigh.  I would need counterweights or springs to help lift it!

My current plan is to make one out of 3/8" plexiglass and secure each edge to 1/2" walnut.  I did find some hinges that would work perfectly for it as they will attach to the TT base I made.  I'm pretty sure I can kill a resonance issue by the inherent weight of the plexiglass and having it close on silicon weather stripping. 

The size is 24" x 30", so 3/8" plexiglass should be heavy enough and thick enough to minimize any vibrations.  At least, for now, that is the plan.

It has been my usual preference to stay mum while reading these kinds of discussions in a somewhat bemused manner.  In my profession, which was to prevent or at least mitigate the effects of dust explosions, Triboelectric Effects, were a serious problem.  The reason was that strong static discharge ignitions can and do occur that result in industrial explosions.  In the playing of vinyl records it is an on-again, off-again nuisance, but it is only a nuisance. Nevertheless, I do have credentials in the field so to speak and feel compelled to weigh in here, in an attempt to sort out some of the confusion.  First and foremost I will admit that I am not particularly interested in the root causes for static buildup on records.  I simply accept that sometimes we experience static buildup on our records and it is best to reduce or eliminate it when it occurs.  My reason is simple, the level of static buildup that we experience on our records never reaches dangerous levels.  So my strategy is when I experience static I want to reduce it acceptable levels.  There are a number of ways to do that such as neutralizing guns, mats, arms etc, all have been discussed earlier in this thread.  AFAIK, any would be OK. I will side with Lewm that the simple act of playing our records does not generate significant static.  Perhaps the record brush many of us apply before dropping the needle does generate sufficient static to be worth mention.  To me that is more likely.  I am also not a fan of closing the dust cover during play, but hey it is your turntable and if you live in a dusty house, who am I to tell you what you should do?  Personally, I change the filter in my HVAC system quarterly or more often to keep the house dust load to an acceptable level.  As others have suggested, in cold climates where central heating systems may result in low overall relative humidity, a humidifier could be beneficial and would certainly be worth a try.  The key take aways here are that static is a nuisance, it is not dangerous, when it happens there are any number of devices that work to reduce it - take your pick, and there are things you can do to improve your home environment that will reduce but not eliminate the problem.  I hope some of you find these comments helpful and constructive.