Presonus HP4

These do sound much better than your stock headphone input found in most devices these days.

Aber besser als andere günstigere Modelle

This is also an example of valu for price performance. If you don't want to spend a lot of cash for your simple home studio, this pre is a go. I have paired it with my Scarlett 2i2 2ndGen and Presonus sounds better not only louder. This is necessary for good studio cans for mixing and mastering.

I really don't see any flaws in this unit. It does the job i wanted it to do, and does it well. Granted, i'm not a studio professional so i can't comment on how it sounds, but at least it has no obvious flaws.

EDIT: after a few years of using it, some flaws have appeared. One of the outputs is pretty much dead now. The other one has stereo imbalance on lower volumes, and has a scratchy and noisy volume knob. The other outputs seem to be okay so far, so it's not all bad, but i guess you get what you pay for.