Odd OMNI/Mac Behavior

[Peter Baird]

Anyone seen this?

I have the Mac Pro optical output connected to the A optical input port on the OMNI, and the OMNI is set to accept 2-channel S/PDIF optical on that port routed to inputs 5/6. When I first boot up the computer and the OMNI the input meter for channel 5 is full on with no audio present (at least none that humans can hear). If I ignore this and start a session the left monitor output will distort in both monitors and cans. However if I start iTunes and play a bit of a song the meter will drop back to zero and the distortion will go away.

Thinking this is related to the CoreAudio issues?

Peter

[Bushpig]

Peter,

I have 2 X 2009 Mac Pro's, and they exhibit this exact behaviour (in fact usually heavily weighted to the LHS, but with plenty of gunge on the RHS as well).

Every time the computer starts up from being shutdown completely, I have this massive "non-audio" signal present on the optical out's (I use a Rosetta 200 here at home connected to the optical ports). It's very annoying and I have no idea why it is, but I now have a little half second blank Quicktime file on my desktop, that I just quickly click on every time the computer has finished booting, to clear the optical port. Doesn't happen through a normal "restart", only from cold boot.

You're not alone. If you find out any info about why this is, I'd be interested to know what causes it. I was hoping when I recently finally went up to Mountain Lion from Snow Leopard, that this issue would be fixed either in software or an EFI update. Nah. Still exactly the same on both machines.

Cheers.

Steve Bush

[jbrown7282]

I think its an OS X thing..... I don't have my Mac Pro Optical set up the way you do but I def need for the computer to pass an audio signal before I use the Mac Audio.... My recommendation if possible is to have your Mac OS audio out on a monitor controller if possible so you can avoid this issue.