Static shock with simple se

[pforeman]

I've made 4 identical simple se's. Mine lives in the basement with cement floor, no carpet. No static shock.
The other three live in friends living rooms. They all shock people when they touch the volume control. If you touch the painted metal case first, you get no shock.
Is this common/normal.
Most appliances today use a two prong electrical cord, but I have plenty of tools etc. that are grounded through a electrical cord and they don't shock you.
Is there a way to run a ground wire or something to the carpet?
Did I do something wrong?
.5 ohms or less measured from vol. control (etc) to ground pin
The other owners seem happy, but my wife is afraid someone is going to die!
Thanks,
Paul

[Soonerorlater]

Hi phoreman,
Sounds like static charge is building up in your friends then going to ground through the control knob.

suggestion- plastic knobs ( I like those chicken head ones )

Best Regards Bill

[rknize]

Is the chassis painted? That may soften the discharge so that the shock is not felt compared to when they go to touch the volume control. Plastic knobs would be a simple fix. To improve WAF, plug one of your grounded tools in near the same location and perform the same actions (walk around the carpet with wool socks and touch it).

It's that time of the year! Buy a humidifier.

[kevinkr]

Originally Posted by Bill Massey

Hi phoreman,
Sounds like static charge is building up in your friends then going to ground through the control knob.

suggestion- plastic knobs ( I like those chicken head ones )

Best Regards Bill

My recommendation too.

Carpets and people make excellent Van de Graaff generators - the knob provides a low impedance discharge path. Completely normal, and not an indication of anything but the fact that the humidity is low.

Linky here: http://en.wikipedia.org/wiki/Van_de_Graaff_generator

[Glowbug]

When I was in my apartment at college, it was always dry...I'd get bitten by the ARC preamp every time.

[Gorgomat]

Hey Paul,

better ground the devices before they ground you.

Best regards,

George

[tubelab.com]

better ground the devices before they ground you.

.5 ohms or less measured from vol. control (etc) to ground pin

Sounds like he did.

I live in Florida where you can't generate any static even if you rub two nylon cats together. The humidity is usually high even in the winter and the heater gets used 1 or 2 days every few years (this year was the exception). I was in West Virginia during Christmas and I couldn't get used to the fact that I could walk across the carpet with bare feet and generate a spark. My laptop rebooted every time I touched its side. Hard rubber or plastic soled shoes are really bad.

Chances are that there is enough carbon or metal in the pigment used in the paint to drain your charge when you touch the paint first. The volume knob should be grounded (as it is) for safety in case anything should short out inside the amp. It would not be wise to change this. If the owners get a similar zap by touching other grounded objects (the metal screws on light switches) then it is just normal static.

[Soonerorlater]

I'm curious as to why people don't initially get a shock when they touch the painted metal case. How does paint, " soften the discharge " as rknize puts it. Does the rate of discharge play a big part in the triggering of the shock sensation?

Brgds Bill

[nic6paul]

One of these should help out
Silver Rock Signature Knob: Reference Audio Mods

[rknize]

It's the arc leaping to/from your skin that hurts. If you hold a key or other metal object in your hand and touch the problematic surface with that, the arc jumps from your body via the key and you don't feel a thing.