Funny reading this thread BTW. And I'm guilty too here... At one extreme we have recogintiion that some of these devices (although it seems rarer in the US) could quite literaly kill you and at the other a seemingly casual just take the cover off.

Perhaps that again higlights the dangers (and I stress I'm aware I contributed) of asking this type tech question on a primarily music forum.

Between us all (and with very informative comments from John in K too) the reality to me (at least if it was common UK systems) is that we could have "killed some fucker" here and all with good intentions.