Earthed power cables on double insulated amps

[aussievintage]

2 hours ago, andyr said:

 

No, I haven't worked on a production line, av.  

 

 

Interesting that you assume industry=production line.    Mining, refining, chemical plants, service industries, engineering works etc etc etc - all exist with abundant safety rules.  You even obey them when you are driving (I hope).

 

2 hours ago, andyr said:

In that environment - sure, safety regs are of paramount importance.  This thread is about home electronics items.

 

So you don't believe the government should have any electrical safety rules to keep you safe from your electrical equipment faults?

[audiofeline]

5 hours ago, andyr said:

So 'Safety' is promoted - at the expense of function?  (Better RFI shielding from the case being earthed.)

I trust that both Class I and II designed devices that meet the electrical standards will be safe. 

However, when looking at audio equipment there are design aspects which may enhance the function of one design compared to another.  When cost can be an option (eg. general consumer level) function is often compromised.  At the high end, we would expect function drives the cost.  However, in the audiophile landscape, profits can still override quality.

[Bronal]

1 hour ago, audiofeline said:

 At the high end, we would expect function drives the cost. 

 

Well I can tell you one trend that certainly doesn't - the location of on/off rocker switches at the rear of the device.

 

Very convenient if the equipment is in a rack!

[bob_m_54]

20 hours ago, andyr said:

 

So 'Safety' is promoted - at the expense of function?  (Better RFI shielding from the case being earthed.)

 

Safety is the paramount feature of any domestic appliance. The purpose of the case of Audio equipment isn't for RFI/EMI shielding, it's for safety, and basically to contain the gubbins (technical term) of the equipment.

 

Contrary to what some people think, RFI and EMI aren't really that big a problem in a domestic situation. If it were such a big problem, you would never see any AV equipment contained in a plastic case. They would be built into full metal enclosures with RFI gaskets. For the small amount of EFI/EMI that may be problematic, a metal shield connected to the zero voltage reference of the equipment (signal ground) and well designed filtering is generally enough.