AW: late one : To earth, or not to earth...

[Haible Juergen]

	>That's it!
	>Now, would it be a stupid idea to do this in a modular synth:
Every
	>module gets not only it's own regulator and overvoltage
protection
	>(this is good practice) but also it's own trafo , rectifier
etc., i.e.
	>now the modules have no ground connection to each other.
      [...]
      >Ok, this is a bit exaggerated, but it shows the idea. 

I had this thought as well, but ...

	>I never had problems with consumer hifi stuff, because there
are no
	>ground loops, all chassis are separated from earth, the
internal trafos
	>are insulating types, safe. All devices have their own power
supply...

Usually you don't make hundreds of connections across
your living room with HiFi stuff. Everything would be star-connected
to your preamplifier. That's why it works.

On a large modular system, you'll build large loops all the time.
Whether the shield (=ground) of the cables that form a loop
is connected to earth ground or not is not that important.
You'll have a ground loop, and the omnipresent 50 (or 60)
Hz magnetic field will induce a voltage into this loop.

JH.