Naim mu-so electrical leakage on metal chassis

I don't touch the Muso, just listen to it. But will give it a try to see if I have the same experience.

I have the same thing with apple products namely the iMac metal chassis I used to own and now a thunderbolt display of the same look, if I am plugging a usb in on the side or what ever and my arm scrapes the metal work it feels most odd, like tiny pins being driven in or something.

It sounds like the Muso may be a double insulated design. ( on the case there will be a symbol of a square within a square). In which case there will be no direct connection to earth. The device uses its external metal case as a shield, but this is not directly earthed, but instead internally grounded. Such devices have advantages with the avoidance of earth loops, reduction of Earth noise, in or out, and cost.

However such devices mean leakage current perhaps through stray device capacitance will couple to the ground .. This can be made more prominent with SMPS or RFI on the mains as higher frequencies tend to couple easier. You may feel this leakage current as a tingle. It is typically harmless and will have been type tested for compliance.

If the Muso is not however double insulated and is therefore directly earthed, it could indicate a possible issue with your supply earth, possibly made worse if you have PME.  .. But I suspect this is unlikely unless you are suffering from nuisance earth tripping. In which case get an electrician in  to check.

Simon

Thank God for that. I was worried we might have a fried duck after Bert's reply. Phew.

Well I don't have any problems with earthing in my home and have never had anything trip unless there was really a problem which was once in a blue moon (but it was a good way to know the breakers were working). 

I do feel it as a tingle, or an ant-bite like I said, because it bothers me enough to avoid touching the mu-so at all.. which is a shame because I thought the volume wheel was nicely designed and functional.. but does nobody else feel what I'm feeling at all? Do I really have thin skin on my fingers?

The Mu-So is  a two wire mains and the tingle is caused by leakage current to the casework and is at a low level which has passed all worldwide safety requirements for this type of product.

All units are tested at the factory but some people can feel the earth leakage more than others.

Can you try turning around the connector from the mains lead at the Mu-So to see if the polarity makes a difference , it’s a figure of 8 so is easily changed 180 degrees

I have noticed this effect if you stroke a naked lady lightly - on a bed with the electric blanket still on. The effect is stronger with two.

Possibly more relevant on a hifi forum -

only yesterday I 'had the tingle' off the metalwork of my charging iPad. I jumped out of its way pretty damn quick.

I believe it to be entirely safe and, even, mildly stimulating.

 Would that be two naked ladies, or two electric blankets

Same thing with older mac-pro that i use occasionally.

He wants to be careful, PVC melts at 130 Deg C.

Only on an audio forum.

Which was why I removed the (joerand) clarifications.