surdo wrote:And to answer fill35U's question: the amp is plugged into a surge-guard and this is plugged into 220v, 60Hz mains outlet. As I mentioned earlier the outlets in this apartment are not earthed, unfortunately, that's the situation, but I am moving shortly to another property where I can ensure the sockets are earthed.
From the photos above, to me at least, the power supply does not seem to be modified and lacks an earth.
Now I'm not a smart guy- in fact, likely the opposite. But I think a little more info would be useful:
Surdo's dwelling has no earthed outlets. How is he going to ground *anything*? Sure, he could run a wire to a water pipe. But it's a rental apartment- how does he verify the integrity of the pipe to ground? Does he drive his own ground rod? Tie in to structural rebar for an "Ufer"? Lay out a huge counterpoise?
Where does he stop? Does he bond just the Sunfire to ground? Set up a bus and run wires to all of his equipment and appliances, even the portable ones, that aren't double-insulated?
Might as well call an electrician, and have earthed wiring and receptacles installed- if his landlord will let him.
I don't know much about power distribution, even less about how it's done in Brazil, and not the foggiest about how Surdo's apartment is actually wired. But is it possible that his 220V is derived from a center-grounded Y (220/400V), or even a corner-grounded delta? Is one conductor of his 220V a neutral?
I wholeheartedly agree that the chassis should be connected to earth *somehow*, either via a separate ground conductor, or the neutral by a polarized plug. Any chance there's an impedance grounding network between a neutral conductor and the chassis in that thing (caps, diodes, resistor?). Hopefully enough to trip a protective device...
Edit: There's always GFCI's...
Just my random thoughts, thank you all for indulging me...