[Amps] Direct rectification of AC mains to derive the amp, VDD, supply

[Jim Brown]

On 9/19/2013 8:37 AM, Manfred Mornhinweg wrote:
>
> the near electrocution you describe was due to several concurrent 
> problems: The short circuit due to a poor solder job, lack of a ground 
> fault interrupter, and poor grounding of the equipment. 

And that is PRECISELY why safety regulations are written as they are. 
I'm a member of the Audio Engineering Society Standards Committee, 
member of several working groups, and vice-chair of the WG on EMC. Most 
of those who participate are from NA and EU. These working groups 
consist of MANY very smart and experienced engineers, and the 
deliberations that produce our standards involve working through a lot 
of "what if" situations.

Likewise, I worked for more than 15 years as a consultant designing 
sound systems for public buildings, as part of an architectural design 
team typically consisting of engineers from a dozen or more disciplines. 
We also worked through a lot of "what if" conditions, and each of us had 
the experience of having one of our own ideas shot down for very good 
reasons we hadn't thought of.

The world tragedy at the Fukushima nuclear facility is an excellent 
example of the failure of that sort of process -- electrical power was 
critical to cooling the reactors, there were multiple generators and 
backup generators, but all were at lower levels that flooded, so they 
all failed, and all the reactors turned into disasters.

Most people I know consider human life safety vastly more important than 
building power amplifiers in a manner that makes them a bit cheaper or 
more efficient.  There are very good reasons for these safety standards 
and codes. Only a fool would ignore them.

73, Jim K9YC