Re: Ground lifting to kill noise
Yes, sounds like the house mixer and your amp are at different ground potential, get a DI with a ground lift and try that.
If you go to a 2 prong adpt. then you will have no ground on your amp, and then you will get lots of noise.
Another thing=the outlet you are plugged into , or the house PA may have a bad ground
If you haven't watched that link on my previous post, you really should, you will learn a thing or two, it's very informative.