2. analog
  3. 163955-129831

Back To Static!

We had a long discussion on the possible causes of static electrical charges on records in another thread. We just had a real good cold snap in New England dropping the humidity to under 20% so I was able to run a set of qualitative experiments documenting some surprising results that I hope will clear up a lot of the mystery and help people contro static charge and the accumulation of dust on their record. 
Static field meters are expensive.  The cheapest one I could find cost $260. I had to find a more sensitive way to measure static as it became apparent that using your own hair is very insensitive. Studying the Triboelectric series I noted that polypropylene is at the opposite end to PVS.  I have polypropylene in the form of suture material, the blue thread that many of you have seen. I tied a length of 6-0 Prolene  to a wood dowel and it worked beautifully. The PVC attracts it like a magnet and the Label repels it. It will pick up very small charges that otherwise go undetected. I can now define four conditions; No charge, Light charge, Charged and Heavily charged. It turns out that completely discharging a record is not easy. The label will actually donate electrons to the vinyl over time reaching an equilibrium point. Totally discharging a record required using a Pro-Ject conductive record brush wired to ground. If I suspend a discharged record (no thread activity) by it's hole within 30 minutes it will develop a slight charge (vinyl attracts the thread, label repels it). This will appear to us as an uncharged record. 
Does playing a record increase the static charge?  Yes absolutely, and the charge is additive. Playing the record over and over again progressively increases the charge from slightly to heavily charged. 
Does how you store the record effect charge? Yes absolutely. Records stored in MoFi antistatic sleeves come out with the baseline small charge. Records stored in paper come out with a noticeably higher charge. These are records that have been totally discharged prior to storage. A record that is charged when you put it away will come out at least as charged even if you are using anti static sleeves. Do conductive sweep arms work? Sort of. If the sweep arm leads the stylus charge will still accumulate. The brush has to track with the stylus. 
Unfortunately, I could not get hold of a Zerostat to test it's effectiveness. Regardless, a charge will accumulate with play.
The single best way to totally discharge a record is a conductive brush wired to ground. Just holding it will not work as well. The impedance of your tissue is in the megaohms. You want a dead short. Even so, a small charge will accumulate over a short period of time. The safest assumption is that there is always a charge on the record attracting dust. So, don't leave records out for any period of time. In regards to the hot topic of dust covers, a properly designed Dust cover does not affect sound quality. If your dust cover does effect sound quality in a negative way then you have a choice between sound quality and dirtier records. Your records, your choice. 
I would love to be able to stage voltages. If in the future I manage to come up with a static field meter I will repeat all of this in a quantitative way. Humidity is a huge factor. Those living in more humid environments have less trouble with static accumulation. I suspect everything occurs in like fashion just the voltages are lower. Lower to the point that they do not need any device to lower the charge?  I don't know. 

128x128mijostyn
slaw's avatar
slaw
22,042 posts
 
My reason for posting was to show that proper grounding is a big factor to getting static under control, as @antinn  wrote in the link he provided. My mentioning of my use of MyMats was to show that with proper grounding, I'm having no issue using them.

@mijostyn, asked me to try the ESD mat. Why would I want to when I'm getting excellent results?
lewm
13,296 posts
 
Magnetization and static charge are two different things, even though both result in an attractive force between two objects. But don’t expect a demag to have any effect on an existing static charge, except where the charge might jump from the object to the demag-er, just by chance and proximity. (In response to Elliot's post.)

Mijostyn, Besides the fact that paper and vinyl may be at opposite ends of a tribo-electric chart, what is the basis for your hypothesis that the charge is ping-ponging between them? Have you experimented with an LP from which the paper label was carefully removed? That might be useful.

In the white paper on static charge vis LPs, published in the 80s, Shure Corporation scientists pointed out that if you remove the charge from the surface of an LP sitting on a platter, the reverse side, which sits against the platter, will retain whatever charge it had a priori. As soon as you remove the LP from the platter, any residual charge on the non-playing surface will re-distribute itself evenly over both surfaces. I think that rapid process of charge re-distribution is what sometimes one hears when removing an LP from a platter, as a faint tinkly sound.
mijostyn's avatar
mijostyn OP
8,570 posts
 
@lewm The hypothesis is based on the fact the every single record that you neutralize both sides, label and PVC will develop a small charge within 30 minutes, PVC going negative and the label positive. This is with the record hanging on a wooden dowel touching nothing else I did is not coming home and no well but air. The only sure fire donator of electrons is the label. So I think it is a safe assumption that electrons are moving from the label to the PVC. It is however not proof. Removing the label on a record and stabbing what it does after neutralization is an interesting experiment to try. I will see if I can do it by cleaning off the label with the bench plane. Shure's remark about charges redistributing is very compatible with the above finding and I think you are right in assuming that charge redistribution is causing the snapping you hear.  Electrons move!

@slaw , Grounding the platter may be useful but only if there is a path to ground.  This would work better with a conductive mat. I cannot run that experiment because I do not have a conductive mat at this time and with my new turn table the mat is a vital part of the vacuum mechanism.

@Elliotebnewcombjr, Others are giving you good advice! Keep that demagnetizer away from everything but your R2R's heads. The mythology surrounding de-magnetization is dangerous and possibly destructive to certain items like cartridges. 

I will report back about the label removing experiment. I will try to remove the label from both sides of an old record and then I will thoroughly discharge it, hang it from the wound dowel and see if it develops a charge. If no charge develops I think we have safely proven that the electrons are being donated by the label.
slaw's avatar
slaw
22,042 posts
 
@mijostyn,

To be clear, I said I grounded the motor, although I did connect the ground to the cover plate on the bottom which is the only area that VPI connected their ground to. If that is run to the platter, I don’t know.
slaw's avatar
slaw
22,042 posts
 
What may be important to add hear is my belief that connecting back to the mechanical bearing is a no no. This is done by using a spindle clamp. I designed the MyMat in part to avoid this. The MyMat system is designed to decouple from the platter and bearing.

I think @antinn should try my MyMat system.

I’ve been out of selling mode partly because it’s not my favorite thing to do and I’m almost out of final stock.

Just sold two last week, the complete MyMat system. Price increase time?
More to discover