Hi, I'm new around here and I need some help from you guys 
I connect my guitar into the back instrumental inputs (the front one is pretty abused by the previous owners) and there is an issue that sometimes my input makes noises, but not pleasant ones, oh hell no... It sounds like scratching/frying something. I checked it with ever possible cable and on both left and right inputs. Only when I plug into the second input and turn the input 1 know to zero it stops. And there are the questions I'd like to ask you: Any idea what can be the cause of that? And second - How to get an actual signal output out of the second input and is it even possible?
I connect my guitar into the back instrumental inputs (the front one is pretty abused by the previous owners) and there is an issue that sometimes my input makes noises, but not pleasant ones, oh hell no... It sounds like scratching/frying something. I checked it with ever possible cable and on both left and right inputs. Only when I plug into the second input and turn the input 1 know to zero it stops. And there are the questions I'd like to ask you: Any idea what can be the cause of that? And second - How to get an actual signal output out of the second input and is it even possible?