I have a digital audio G4 with dual MPC7410 CPUs. The machine has a
Radeon 9000 Pro graphics card and a M-Audio Audiophile (Envy) sound card.
I can get the sound card working fine if I boot the machine to Linux and
compile and install the kernel and ALSA drivers clean. It seems though as
soon as I reboot into OS X and use it for awhile, then return to the Linux
setup (Debian unstable) the sound card will no longer operate correctly.
Horrendous digital noise comes from the speakers when attempting to play
any sound/song file. I have experimented with all the settings in
envy24control and the alsa setup program to no avail. I have posted about
this problem to the ALSA mailing list and no one answers or seems to have
any insight as to what the problem is. Quite frankly, I have not been
able to discover the sure fire repeatable way to show the problem. One
other theory is that apt-get update/apt-get dist-upgrade, installs or
changes the config somehow as the card seems to stop working after that
too. I am trying to come up with a method to check that theory too.
I am wondering if OS X is somehow changing the setup of the card through
OF or some config ROM on board the card. Are there any tools that can be
used to save or examine the complete state of a card on OS X and Linux so
that I can compare the two?