Prickling sensation when touching WiiM Amp

[onlyoneme]

You might use a ground of unused rca inputs or sub out to make a cable for earth grounding if you don't trust the floating design.

 

[harkpabst]

... but to emphasize that all units behave consistently, meaning it being normal (or not) for all units and not related to a fault in the setup.

Good to hear that.

I didn't experience any prickling so far with my only WiiM Amp, which has no external connections except for the power cord.

 

[Brantome]

Must admit I get a little nervous when I see bare wires If you're in any way unsure about the above images, for safety reasons please consult a qualified electrician

 

[Wiimer]

Is this measure necessary for WiiM amp without prickling? I'm ignorant about earthing, so someone can tell me.

 

[Brantome]

Fine, I hear what you're saying, but in terms of safety, liability etc, I prefer in all the groups/forums I help manage to issue the standard advice to consult an electrician if unsure rather than implicitly sanctioning what's been posted by not commenting

 

[harkpabst]

Is this measure necessary for WiiM amp without prickling? I'm ignorant about earthing, so someone can tell me.

It is safe to use without additional measures.

Disclaimer:
I'm just repeating what WiiM officially declares here in this forum and by printing the corresponding certification marks on the device. As an EE I see no reason to not trust into this, but this is still just a personal opinion.

 

[Wiimer]

It is safe to use without additional measures.

Disclaimer:
I'm just repeating what WiiM officially declares here in this forum and by printing the corresponding certification marks on the device. As an EE I see no reason to not trust into this, but this is still just a personal opinion.

Thank you.

 

[amix]

Hi,

With two of my four WiiM Amp I've noticed that, when touching the case, there seems to be some level of electric current present on the metal casing.

My mom's MacBook does that, too.

 

[mlsstl]

Haven't seen anyone mention this yet, but have you used a socket tester to check the wall outlet? It is not uncommon to find miswired outlets that either have the hot and neutral wired backwards or a faulty ground. Older houses may be more likely to have problems but mistakes can also be present in new homes. Wall outlet testers are available for $10 to $20. (Note: the OP didn't say where he's located. I'm based in the U.S. but assume there can be wiring mistakes in other countries.)

 

[harkpabst]

Note: the OP didn't say where he's located. I'm based in the U.S. but assume there can be wiring mistakes in other countries.

Indeed, he did not. However, in general there is no clearly specific hot and neutral wire. With AC it simply doesn't make much sense. Therefore devices must not rely on one of the two contacts being neutral.

Safety ground is another topic (especially in older buildings), but doesn't apply here, since we just have a two wire cable.

Edit: Just added the all important word "no" for this posting to make any sense ...

 

[WiiMer SJ]

If I were experiencing this issue, which I am not, I would at least install something like this:

Anti-Static Mat ESD Safe for Electronic Includes ESD Wristband and Grounding Wire, HPFIX Silicone Soldering Repair Mat 932°F Heat Resistant for iPhone iPad iMac, Laptop, Computer, 15.9” x 12” Grey https://a.co/d/5lLPaFM

The above is offered as an example, and is obviously designed for the US market. I'm sure there are comparable products for other markets and power distribution systems. It will not resolve the problem, but it will provide a margin of safety for the user and the equipment.
Given the attention this issue is receiving, I predict Wiim will revise the method of connecting mains power in future versions of their products.

 

[WiiMer SJ]

Ask myself what my wife would tell me if she see me standing in front of my audio wearing a wristband, wired and standing on a grounding mat. She surely would prefer a burgundy red one ;-)

Mine stopped rolling her eyes at me a long time ago.

The idea is to touch the mat when touching the device. The wrist strap is optional.

 

[Wiimer]

I'm wondering if I should throw these into my Amazon cart.

 

[WiiMer SJ]

I'm wondering if I should throw these into my Amazon cart.

Sure.

 

[mlsstl]

Indeed, he did not. However, in general there is no clearly specific hot and neutral wire. With AC it simply doesn't make much sense. Therefore devices must not rely on one of the two contacts being neutral.

I see you're in Germany. In the US, house wiring does have neutral and hot wires. 120 volt wall plugs are supplied by one of the two hot (black or red colored) circuits coming into the house. The hot wire is 120 volts over neutral (white), so the 60 Hz voltage swing takes place wholly above neutral. A third "ground" (bare) wire is present for additional safety. The other hot wire coming into the house is 180 degrees out of phase to the first hot wire, so when you have a socket that uses both hot wires, you now have a 240 volt circuit for appliances like stoves, dryers, AC and the like.
Back to the original subject, wall sockets can be wired incorrectly and this can be one cause of tingle the OP is experiencing. Hence, $10 or $20 for a wall socket tester is a good investment.

 

[harkpabst]

Back to the original subject, wall sockets can be wired incorrectly and this can be one cause of tingle the OP is experiencing. Hence, $10 or $20 for a wall socket tester is a good investment.

The WiiM Amp does not use the ground connector.

The plug that goes into the amp can be put in either way.

Therefore it doesn't matter if L and N are wired the correct way around in a Type B NEMA socket (or Type G "Commonwealth Socket or Type E CEE 7/5 or whatever socket).

There are just two wires that can be switched back and forth at the amp every time. What kind of error exactly could a wall socket tester detect that would lead to what the OP is describing?

 

[mlsstl]

There are just two wires that can be switched back and forth at the amp every time. What kind of error exactly could a wall socket tester detect that would lead to what the OP is describing?

I've bought several different houses over the years and an inspection, including electrical, is always part of the buying process. At least two of them had a few sockets wired incorrectly. I've simply offered the idea as a something to check as it is easy to do and the devices are inexpensive. Of note is that every Wiim amp the OP has seems to have the problem to some degree. If a design flaw there would certainly be a lot more complaints. And it seems unlikely the OP is the only person who received multiple defective units when there have apparently been no other complaints, at least that we've heard of. Given those factors, the problem seems likely to go back to something about the OP's environment.

I've offered my two cents, so the OP can use it or ignore it as he sees fit. No need to beat the issue into the ground. Hope he finds a solution.

 

[nonloso]

Appreciate the explanation! And my apologies, I did not mean to presume it being a design flaw, but to emphasize that all units behave consistently, meaning it being normal (or not) for all units and not related to a fault in the setup.

Regarding "as can you" - well, for most of my Amps I'm just playing music on some bookshelf speakers, using a WiFi source, so there's nothing nearby to connect to.

However, as long as it's indeed safe and normal, this doesn't bother me.
Thanks also to support for pointing out that it indeed _is_ both safe and normal.

Just tested once more:

- Myself standing on the floor (any room, tile or carpet), especially with bare feet: prickling.

- Plugging in HDMI to TV: prickling stops.

- Detaching myself from the ground (e.g. small ladder with plastic steps): prickling stops.

This is identical behavior for all four of my units now.

Still wondering if this is safe though (especially because connecting HDMI seems to ground it).

Have you tried reversing power plug? In my experience, some devices show a stronger effect depending on the polarity of the plug.
Probably related to the fact that in Europe usually the neutral is also connected to ground, and to how the case is capacitively coupled to the power supply line.

 

[harkpabst]

I've offered my two cents, so the OP can use it or ignore it as he sees fit. No need to beat the issue into the ground. Hope he finds a solution.

I didn't question your experience as a house buyer and I'm not discussing anything away. I'm just asking how incorrect wiring could possibly cause the phenomenon.

I take it you don't have an explanation. No need to be upset.

Have you tried reversing power plug? In my experience, some devices show a stronger effect depending on the polarity of the plug.
Probably related to the fact that in Europe usually the neutral is also connected to ground, and to how the case is capacitively coupled to the power supply line.

This definitely is a real thing, but shouldn't happen to a device that isn't connected to ground (Type C plug, CEE 7/16).

Trying it doesn't hurt and costs absolutely nothing. I just wouldn't bet my money on it.

 

[mlsstl]

I didn't question your experience as a house buyer and I'm not discussing anything away. I'm just asking how incorrect wiring could possibly cause the phenomenon.

I take it you don't have an explanation. No need to be upset.

No skin off my teeth. I see only three possibilities. 1) a bad design. 2) multiple units with identical defects that weren't caught by QC, all sold to one individual. 3) Something in the OP's setup, other equipment or house that is adversely affecting the units. Take your pick.