Ruby Tuby Amp - any dangers?

[GreenEye]

Silly question, but I'd rather be safe and blatantly noobish than sorry.

OK, so are there any dangers of shock with the Ruby Tube amp? I guess using a 12V wall wart, only 12 volts could get through to the board, so I guess I could get shocked with 12 volts, huh?  Is this much of a concern?  Does one still need to follow the safety rules for working on something like a tube amp, or are there some "junior rules" to follow?  One hand in the pocket and such?

[bancika]

It should be safe, but I wouldn't really grab ground in one hand and 12+ in other. Transformer is more than 300ma and it's more then enough to kill through heart 

[calpolyengineer]

Well, UL (the folks that approve electronics stuff) say that any metal carrying 50V+ cannot be exposed more than 1/16". They set up this rule based on the principle that if you blindly stick your hand in there and prod at everything, you won't get shocked. So, since the UL says its more than safe, I would have to agree.

-Joe

[Ge_Whiz]

It should be safe, but I wouldn't really grab ground in one hand and 12+ in other. Transformer is more than 300ma and it's more then enough to kill through heart 

The resistance of the skin is more than enough to ensure that 12V is nothing like enough to drive the full 300 mA through the heart, nor anything like it. It takes about 40V in extreme conditions (small child, weak heart, salt water on skin etc.) to lead to a dangerous situation. However, it's always worth taking precautions with valve circuits just to get into the habit.