i'm brand new here but I think I found a way to solve this problem !!
first of all I'd like to thank all the guys who are keeping this site and forum alive. i've been looking for years to see such a site, struggling with basilisk and sheepshaver nights and week-ends until i found you !!
now my sheepshaver runs a MacOS 9.0.4 like a charm!! and my basilisk, a honorable MacOS 7.5.3!!
I almost cried when I started Beyond Dark Castle on that machine!! So many souvenirs...
anyway, for that sound issue, i narrowed it down to 2 files : In the system folder, replace the file "System" (suitcase file), and in Control Panels folder, replace Sound.
I replaced those 2 files with their equivalent from the 9.0 image I found on this website : http://www.redundantrobot.com/sheepshaver-tutorial/
actually this 9.0 system image works well but it's a very minimal system (without internet, etc...) so when i looked for something better, i found this explanation from Ronald (whom i'd like to thank very much for that)
http://www.emaculation.com/forum/viewto ... r&start=25
So i extracted a complete 9.0.4 system from a powermac G4 software restore disk, and it worked totally fine, expect for this sound issue.
but now it's fixed and i'm the happiest guy in the world !! i'm back in the "classic" world !! yeah !!