i reinstalled the hole image and updated to 2.37. At the beginning thevsound was just right. I don’t know what happened, but it started to distort again. I shut the system down, rebooted and tested with the raspi attached to my stereo -> good sound. I was happy and thought my active speakers are to be accused. But as I changed back to the speakers the sound was good, too. The raspi was not shut down meanwhile.
I’m really confused. Some time it works and some time it doesn’t.