How do the pros hookup differential amps to o-scopes?

[Rudy]

if you isolate your scope ground from earth ground and everything else you can simply use the scope ground lead on one amp and the hot lead on the other.........

Possibel, but , why not the other way around ????

i assume you grounded your amp, so disconnect the ground from the amp, and make sure that your generator isn't grounded.

I myself use the new handyscope 3 ( build in generator ) , it connect to the pc using USB2, and very inportent, is gets its supply from there to, so if i use my portabel, i totally have no grounding problems, but then again, i never had any kind of grounding problems before 🙂

Nice to know, the handyscope has a dynamic range of 105dB in the FFT mode 😱

Greetz Rudy