Um, i was way to slow...
@Fred
OK, corrected this sinus-sine-thing...
And yes, BT-Chips are acting like that. They are trying to eliminate this greey zone between the Max. and Min. Point of the Waveform. This results in a sharper Picture.
Oh, and the more Horizontal-Lines, the better the sharpness - in 2 ways! More Lines = more Informations AND more Lines = more sharpness of one Line, because the Lines are "smaler".