Help me solve static electricity problem

Not sure what to suggest offhand, but answers to the following questions may be useful in focusing our thinking. I will say at this point, though, that what you are describing sounds to me like it goes beyond normal static effects. My guess is that something is wrong somewhere, in the system or in the ac power distribution.

-- Are the connections between components balanced or unbalanced?

-- Are the ac power plugs of all of the components 3-prong, and is the third prong (the safety ground connection) defeated on any of them via a cheater plug?

-- Are the ac power plugs of all of the components sharing a common ac outlet, via a power strip or power conditioner, or are any of them plugged into separate outlets or separate dedicated ac lines?

-- If you are using a power conditioner, does it separately filter the ac to the preamp and power amp? And what model is it?

-- Is there any likelihood that interconnect cables may have been damaged around the time this started happening, such as by being stepped on?

-- How old are the components?

-- Does the system have protection against electrical surges?

-- Do you feel a mild (or not so mild) static discharge shock when this happens?

-- Do you feel a shock if you touch a component while everything is turned off?

-- Does it happen with line-level sources, phono-level sources, or both?

-- Does the system include a phono stage, either within the preamp or separately?

-- Do you have confidence in the integrity of the house's ac wiring? For instance, is it conceivable that there could be a missing ground wire or open connection somewhere?

Regards,
-- Al

Vhiner -- Well, with all of that good protection and filtering, most likely one of the possibilities I was envisioning, that you have a damaged line bypass capacitor in one of the components, can be ruled out. That was why I asked about surge protection, and also about the age of the equipment.

However, the fact that everything is separately filtered, and the power amp is on a separate dedicated line, increases the likelihood of noise voltages developing between the chassis and circuit grounds of the different components. The degree to which that might happen would depend on the shield resistance of the interconnect cables, which connect the component chassis together. That is why I asked about the possibility of a damaged interconnect. I'm envisioning that the rfi (radio frequency interference) generated by a static discharge could induce noise into any susceptible point in the system, which would then get amplified by everything downstream, causing the pops you hear. A phono input would be a likely suspect, because of the high gain factor that is applied to it.

So besides continuing the interconnect experiments you are already doing, I would suggest:

-- Putting shorting plugs on any unused phono inputs, and/or disconnecting any used phono inputs and putting shorting plugs in place of the cables from the turntable.
-- Disconnect all source components from the preamp, and see if you still get the symptoms when the preamp or power amp is touched.
-- Disconnect the preamp from the power amp, and see if you still get the symptoms when the power amp is touched.
-- As an experiment (to help in diagnosing the problem) plug the entire system into the Guardian, assuming it has enough current capability, and see if you still get the symptoms.

Hope that helps,
-- Al

12-12-10: Heyraz
Anyone with knowledge of Capacitors? What would happen if the chassis of each component were connected in starfish pattern through capacitors to one central ground point and then on through another capacitor to a common ground? Would the capacitors act to absorb the static discharge and then slowly release them to ground? I'm not 100% sure how caps work but they seem to behave like water hammer arrestors sometimes.

That's an imaginative thought, but I don't think it would help. Basically a capacitor acts like an impedance whose value decreases as frequency increases. So it would shunt high frequency energy to ground, within the constraints presented by the inductance of the associated wiring. But the safety ground wiring that is already present will do the same thing, except better since it will conduct low frequencies in addition to high frequencies.

A device called a Transorb is commonly used for dealing with brief but large voltage spikes, but determining how to best apply one within a particular piece of equipment would be problematical.

One approach that I think might work in many cases is a variation of Kijanki's earlier suggestion, about lowering the impedance of the path between each chassis and a common ground point (such as the screw on a wallplate, or the chassis of a power conditioner). But my suggestion would be to do that with braided rf ground straps, rather than heavy gauge wiring, connected in a star pattern as Kijanki suggested. That would present a path for the extraneous currents that is truly low impedance at high frequencies. Industrial distributors such as Digikey carry ground strap material, but typically in large quantities. It is offered in smaller quantities by a number of eBay sellers -- search under "ground strap."

Regards,
-- Al

Isn't static at very high voltage?

Yes.

Would a cap simply look like a resistor to a very high voltage...even if the current were essentially zero?

It would look like some combination of capacitance, inductance, and resistance, with various resulting overall impedance magnitudes and phase angles at each of the many frequency components of the static discharge. But since those impedances together with the impedance of the connecting wires would be higher than that of a heavy gauge wire by itself, and much higher than that of a braided ground strap, the capacitor would serve no purpose.

Re the Zerostat, keep in mind that what we are trying to de-staticize here is the person!

Best regards,
-- Al

Other than wearing rubber soled shoes, a grounding strap, remembering to discharge oneself to ground, or treating oneself, carpeting and furniture to reduce static buildup, is there any component, device or circuit that could replace the "capacitor idea" in my previous design to absorb and pass the discharge to ground without creating a ground loop or other ill effect?

It seems to me that the use of braided ground straps from each chassis to a common ground point, as I described above, might do exactly that in many cases.

Why are some components less susceptible than others?

Good question. My feeling is that the root cause of these problems is most likely the failure of the designers of equipment that is susceptible to this problem to adequately address the issue during the design process.

It's interesting that computers, which contain digital devices and circuits that are much more complex than in most audio components, and that run at much higher frequencies, never (to my knowledge) seem to have these kinds of problems when their metal cases are touched. Makes you wonder.

Best regards,
-- Al