Thanks for your help! I did return the instrument and with the new guitar, the problem went away. I'm pretty sure it could have been a setup problem, but since I'm not able to do it myself and didn't have a technician at hand, I went the lazy route... 
Thanks again!
Yeah, I know what you mean, but my thread wasn't intended to bash the KPA in any way... I just wanted to get the opinion of more experienced users!
So, thanks, guys... I guess, I will just return the instrument first...
I did!
With the tele it's not that noticable and I guess that's because of the lower output PUs...
I always thought that active pickups would be better suited for such high level gain stages... maybe it's somehow releated to the piezo system, although I'm not even using it...
On the other hand, I really need to improve on my technique... 
Thanks for your quick help, guys!
This is not an acoustic guitar, you can completely circumvent the piezos... but I only have a Fender telecaster as an alternative, which generally is not really comparable with these kind of sounds... its awesome with clean to mid-gain profiles though!
I also think it might be related to fret buzzing and bad technique, since I'm not that great of a player, but I just wanted to rule out any technical problems with the unit first!
Hi there,
I'm having a pretty annoying noise problem while playing high-gain stuff.
It almost sounds like feedback overlaying the main sound and - since I'm brand new to the KPA-world - I wonder if this might be a problem with the KPA.
I've attached an example using the "LL-Schmatz"-profile from the Lasse Lammert Rig Pack.
The Guitar is an ESP LTD EC-1000 Piezo, with Seymour Duncan SH-1 '59 and SH-4 JB pickups installed. For this example, I was using the magnetic pickups only.
The problem is very audible at around 13 seconds into the clip, but thoughout the whole take.
It's also not related to the LL-profile only, I'm getting the same unwanted distortion on almost all high gain-profiles.
Reducing the output on the guitar didn't help too much, without loosing that specific sound and there's no clipping going on, wether in the KPA nor on my audio interface.
What's wrong? 
