problem with hum and hiss

[Dimitree]

hello everyone.
I am experiencing some hiss/hum problems (don't know the difference, sorry I'm not english).
when I have my guitar plugged in the amp, everything is fine.
when I plug a truebypass stompbox in the chain, and I don't power it (so only works in bypass) is still fine, but if I touch the pushbutton with my hand, a hiss starts.
when I plug the 9V DC adapter in the stompbox (and keep it in bypass), another kind of hiss adds in (so if I would touch the pushbutton I would have 2 hiss mixed).

where could be the problem? it happens with other true bypass stomps too

[brett]

Hi
might be an issue of inadequate earthing by which you are acting as an antenna.
Possibly the ground/earth at the amp input is "floating". Are the socket and the amp properly grounded?
good luck