Hello Kanru, I saw your message a little late... I just made a clean installation and add the testing repertory. Unfortunately the result is the same, the hiss is still present in my headphones ;( But the installation is very stable for my. This is a perfect candidate to add it on backports repertory. After this, if I add the backports repertory and install the Kernel v. 5.4.0-0.bpo.4-amd64 after reboot => all is ok !!!! Powertop v. 2.11 with Kernel v. 5.4.0-0.bpo.4-amd64 solve the problem :) Now I have a new problem : https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=956203 If you have a Idea for solve this, I will be very grateful to you. Regards. Philippe
