Originally Posted By: Ryszard

Question is, how do I tell whether the mixer is double insulated? It's a Behringer Eurorack MX 2004A. The mains cord has two prongs, but goes thru an external transformer to a cord with a multipin connector into the mixer. I have no problem mucking about with the short (<1 m) audio cables with what look like Switchcraft 1/4" plugs running from the mixer to the PAB.

Final question for this session is, how risky is it to leave the PC plugged into the 3/2 adapter? I'm sure enjoying the noise-free thing here.

Hi Ryszard,
you've answered it yourself:
2 pin plug (from the manufacturer) = no earth = double insulated.

How risky..? How long is a piece of string?

If nothing fails there is no risk at all, but I would in no way advise you to do that.

I have, however, had a thought:

If you have, or acquire, a powered USB hub, you could connect the PC to the hub, and the hub to the PAB. With any luck the earth from the PC would be interrupted at the hub and there would still be no noise, but the PC would still have its earth connected.

Problem is I don't know if the earth would, in fact, be broken at the hub...

OK, just checked on I have and the earth is extended so power can be extended from the hub frown

However, you mentioned being skilled at making cables. Does that mean you'd be happy to have a hack at a cheap USB hub? If so, open it up, identify where the USB power comes in, make sure it isn't needed for the hub to be activated (external power should take care of that (I hope)) and break the tracks or whatever. Make sure you DON'T break them where power from the wall wart feeds USB devices plugged into the hub.

--=-- My credo: If it's worth doing, it's worth overdoing - just ask my missus, she'll tell ya laugh --=--
You're only paranoid if you're wrong!