It's very weird. it works fine when i have it selected as the output in the Sound System Preference. anything that uses the system sound plays fine through the 828 like itunes, sound from websites, and even Ableton Live playing in my windows install with Parallels.

When i goto any "Pro" audio app like Live, Peak, and software synthesizers and choose core audio - 828, then the sound stops working, after a couple of seconds i hear pops & clicks.

I un and re installed the drivers for the 828 and that did not seem to help.

Im runnning 10.4.10 on a 2.2 GHz Mac Book Pro

Be careful with new OS upgrades. I've seen some reports of 10.4.10 being the cause of clicks and pops on Intel Macs (and some earlier G5 systems) so you may want to check there.

Also with my 828mkII it doesn't like it if you launch a core audio app while playing through the system output. I always close down any apps that use system output before I launch my core audio apps (usually Digital Performer) just to be sure and I've had no problems.

Current setup:
PowerMac G5 1.6Ghz with OS X 10.4.9

(waiting to go to 10.4.10 - Slee's post is one of the reasons why)

Hi! I had the same problem.

Set optical output to ADAT, if it is already on ADAT switch to NONE and then to ADAT.
(even if you don't use optical output at all)