I'm a new Kemper owner, had the PowerHead for a month or so. First of all, let me say Kemper is just an awesome product, and I'm very happy with it. I have recorded and gigged with it successfully, and created a few profiles of my own amps myself, with good results in most of the cases.
However, I do have one problem with the actual sound: the attack can be extremely "spiky" when you hit the strings hard. This is difficult to explain, but there is a quick popping sound in the beginning that doesn't happen with a real tube amp. This happens mostly with the first note/chord after a short break, not so much if you play constantly. This can be witnessed with studio monitors or headphones, but is most apparent in high volume with a guitar cabinet. Some profiles are worse than the others, but I think this happens with most of them to some extent.
I have checked that this is not because of any effects in the signal chain, or settings in the Amplifier section, but it does happen regardless. I can also hear and feel a difference when profiling and comparing the reference sound to the profiled sound.
This is getting quite annoying, as this is practically the only issue to me that separates the Kemper tone from a real tube amp.
Any advice? Is my Kemper faulty, or do others experience this as well?