Hi, I got a Kemper a week ago and I am struggling with a Feedback/Squeal issue.
I have a Line 6 Amplifi that I am using as my FRFR and also to Jam along backing tracks as it has Bluetooth. It has really served me well but I wanted to step up my game with a Kemper. I do not need anything bigger that the Amplifi as I only play at home with the Bluetooth streaming at low volumes or Headphones.
The issue I have is related with Ground loops and the Ground lifts in the Kemper. When I use the Kemper and the Amplifi together I have this weird uncontrollable squeal. It is not really a feedback since all of this happens over headphones too.
I have tried this connections with the following results:
Kemper Headphone Output -> Amplifi Aux In = Squal when I stop playing.
Kemper Direct Out (Master mono) -> Amplifi Guitar In (Moddeling bypassed) = Squeal uncontrollably
Kemper Main Out (Master mono) -> Amplifi Guitar In (Moddeling bypassed) = Squeal uncontrollably
Kemper Monitor Out (Master mono) -> Amplifi Guitar In (Moddeling bypassed) = Squeal uncontrollably
Kemper Direct Out (Master mono) [groud lifted] -> Amplifi Guitar In (Moddeling bypassed) = Works OKish
Kemper Direct Out (Git Analog) [groud lifted] -> Amplifi Guitar In (Moddeling ON) = Squal when I stop playing.
Kemper Main Out (Master mono) [groud lifted] -> Amplifi Guitar In (Moddeling bypassed) = Works OKish
Kemper Main Out (Git+Processing)[groud lifted] -> Amplifi Guitar In (Moddeling bypassed) = Very bad squeal.
Kemper Monitor Out (Master mono) [groud lifted] -> Amplifi Guitar In (Moddeling bypassed) = Works perfectly!
Kemper Monitor Out (Git+Processing)[groud lifted] -> Amplifi Guitar In (Moddeling ON) = Works perfectly!
All the test were done with different volumes in the Kemper and Amplifi. Profile is a high gain one as well as preset it the Amplifi when modelling is engaged.
The issue does not happen if I connect the guitar directly to the Amplifi or if I use the Kemper by itself. I also tried a Boss GP-10 into the Amplifi with no issues (well the GP-10 does not have ground connection to the wall).
So my questions are: how do the different outputs differ?
From the tech specs they are basically the same (¼-inch TS unbalanced with ground lift, max output level: +16 dBu) and they are multipurpose based on the setting but they seem to behave differently. It is clear the Monitor Output works differently and the best performing. it is like the only one where the ground lift works as intended.
Am I missing something?
Any help is appreciated.