Getting zapped off 2.1 speakers and sub

[Armadillo]

Your test hookups are proper.
In my opinion, the metal case is supposed to be either doubly insulated Class II or connected to earth, otherwise it will fail the codes. It means you should not be measuring any voltage on the case. Stray Ghost voltage maybe.

There are few situation;

1. The DC power cord may be multi wires and one of them is earth wire which should be connected to the casing. The wire is broken. Or the earth is not true earth [earth broken somewhere else].
2. There is a short circuit in the internal circuit hence you have some problem with the amplifier. The shorts leak to case.
3. Cut exposed wire is touching the metal case.
4. [Append] Faulty power supply.

You should decide "finally" decide if your want to return it or troubleshoot yourself. If you do, I trust a lot of good members here could advise you how to resolve it and repair your amp.
The first thing is seek for any schematic of your amps, just to be sure.   

[shakalnokturn]

That is definitely a dangerous faulty equipment @180mA leakage current. Not only painful shock, it could have been fatal if the shock persisted for over 1 sec. 

Got lost in a coma.... I read 180 micro amperes not mili amperes on that current measurement.



@zetsubou: Your measurements look good.

[Armadillo]

That is definitely a dangerous faulty equipment @180mA leakage current. Not only painful shock, it could have been fatal if the shock persisted for over 1 sec. 

Got lost in a coma.... I read 180 micro amperes not mili amperes on that current measurement.



@zetsubou: Your measurements look good.

Opps!. thanks for point out. Coma yes.

[zetsubou]

Or the earth is not true earth [earth broken somewhere else].

I think this is the most likely issue as the fault shows on the speakers and sub even though they are powered independently..

[zetsubou]

In my opinion you need to return it or at least get them to send out another SMPS, it's not really your job as a consumer to test it however.

Thanks Shock. Unfortunately the unit was purchased a little over 2 years ago. I was in contact with them immediately but ultimately let it go.
Since then, it's sat undisturbed until recently when I reorganised and discovered the issue. I'm afraid I 'own it' 100% 

You've given me an idea though - I'm going to test it on a new GPO. I know the wiring is good at least to the earth junction in the board.

Edit: Same result.

[tooki]

Read it, understand it, and if you are not satisfied, you can write to the board to query their intents.

Steady state 0.5mA may not feel a thing, but if you make contact at peak of AC, there will be a higher instantaneous current that gives you a zap, but if you hold it, you will not feel a thing until you let go of it and grab it again.

I consider the vibrating sensation normal as it happens at as low as a few tens of uA, and I'm totally fine with it.

You may have the rare anxiety disorder or maybe rare sensitivity ability?, but do check your doc.

It's not feeling current through my body. It doesn't feel a thing if I don't move my hand, but if I gently move my back of hands across such a surface, I can feel it's slightly vibrating.

Also, this only works on semi-insulation surface. A fully conductive surface won't work. You can try this on a powder coated microwave, find a dumpster unit with a lot of use (maybe smoke or something has seeped into it, increasing leakage by a bit), cut the ground wire, and measure leakage to ground. It should be in sub mA range, but if you put your back of hands on the powder coated case and swipe on it, you can feel something.

Another case you can try is to find a Macbook before USB-C, and power the charger from a non isolated 220V source without ground, and move the back of your hands on the anodized aluminum surface.

Yep, lots of people notice that on PowerBooks and MacBooks made from aluminum, or indeed even on plastic MacBooks when touching the screws. But indeed, only when using an ungrounded power cord or duck head. (Also, not only on 230V - I noticed it on 120V myself.)

Just as you said, some areas of the skin are much more sensitive, like the back of hands, or the top of your legs (how I first noticed it from screws on a plastic MacBook).

[paulca]

Have you tried touching it with your tongue?

Might be just me, but I have a thing for testing voltages with my tongue.  I can give you a 1 significant figure estimate on a 9V batteries charge with my tongue.   Although this is mains voltage.... so I'd probably not try it.

It's mostly related to how long I feel comfortable with it on my tongue.  If I touch it and instantly recoil, with a lingering pain in the tongue, it's probably near fully charged.  If I can hold it for a second and it leaves a coppery taste but not real pain, it's on it's way out.  If I can hold it constantly, it's a goner.    If there are lots of expletives and spitting it was probably a 12V battery.

[zetsubou]

Have you tried touching it with your tongue?

Hahaha I haven't tried this. If I leave it on my wrist for more than a few seconds, my finger tips start to twitch and start to curl up.
I'm going to move these out to the garage and get a new set.

[Bashstreet]

Have you tried touching it with your tongue?

Might be just me, but I have a thing for testing voltages with my tongue.  I can give you a 1 significant figure estimate on a 9V batteries charge with my tongue.   Although this is mains voltage.... so I'd probably not try it.

It's mostly related to how long I feel comfortable with it on my tongue.  If I touch it and instantly recoil, with a lingering pain in the tongue, it's probably near fully charged.  If I can hold it for a second and it leaves a coppery taste but not real pain, it's on it's way out.  If I can hold it constantly, it's a goner.    If there are lots of expletives and spitting it was probably a 12V battery.

Technically that is a fetish

[stevelup]

If I bought a metal cased device that didn't have an Earth I would point it out to trading standards.  As I understand it, it would not pass British safety standards for mains operated equipment.

Every single bit of kit in my AV rack is metal cased and not one of them is earthed (I'm in the UK too). The only requirement is that it needs to be double insulated.

if I got a mains zap off a metal cased product it would be returned to the vendor with a letter of complaint and a threat of containing trading standards

I think you've been very lucky to never feel this. Perhaps your skin is particularly high resistance... I've lost count of the number of times I've felt this when brushing against the ports on a laptop for example. Interestingly, never felt it on any Apple device.

Some satellite receivers are a nightmare for this with 80 odd volts DC on the LNB connections with reference to ground. It can be a really nasty surprise when you're up the top of a ladder and you touch the grounded dish with one hand and the F-connector with the other...

[Bashstreet]

Hahaha I haven't tried this. If I leave it on my wrist for more than a few seconds, my finger tips start to twitch and start to curl up.

You probably want to see a doctor. Since you've measured 180uA leakage, that amount of current should not cause muscle twitching. You must have a higher sensitivity to electricity, which means otherwise safe devices to other people may hurt you.

Ok please lets stop the bs and nonsense.

Although people perceive electrical current differently "symptoms" of current flowing through body (parts) have same physiological effects.

OP is not "different" or need doctor and my bet is there is higher current leak.

This topic has been full of nonsense stupid advise inaccuracies cock fighting trolling and all sorts.