i had an electric shock with my amp and my audio interface

[pietro_moog]

hi guys.
my amp (5f2-a) is working great, better than i expected.

there is only one problem: i had 2 big electrical shocks!
thing are gone this way:
i was trying my amp, and it was very good. so i decided to record something to see how good was the recorded tone.
i connected my Apogee Duet (do you guys know it? it's an audio-interface,
sounds very good to me. it ha a big metal volume knob) and started recording.

i was playing guitar, i touched the jack (metal body), and the amp.
then i touched the interface metal knob and i had a big electric shock,
it seemed to me very big, bigger that 220v from the wall..


do you guys have any idea of why?
i feel a little scared of that shock..

[Chuck H]

If the two units are of reverse polarity AND there is a ground fault that could explain it. Does your 5f2a have a grounded AC cord? If yes, is the ground lead of that cord electrically connected to the amp chassis? Does the Apogee Duet have a grounded AC cord? And, are you using any ground lift adaptors?

Chuck

[Steve Conner]

Doesn't Italy still use 2-prong sockets like the old American ones?

[pietro_moog]

no, we have 3 prong sockets too. it's a yield of modernity.

i take some measurement. i have a 220v difference between my rack and my guitar. i need to take some others.

i'm not sure the socket i connect my rack up is connected to ground.
i thought about it now.

[pietro_moog]

i took some measurement and i found out that i have a big grounding problem in my house. gear is fine

[Steve Conner]

OK... well hope you get it fixed and don't get fried!

[Chuck H]

While your at it, check to see that the polarity is the same on all your outlets. With AC it's the polarity difference that creates voltage potential across two points.

Chuck