How to bypass AC3 on Mac mini?

[srobert]

Hi,

 

I'm new here and hope this isn't a stupid question.....

 

I have an Intel Mac mini running digital optical out to a modified LiTe DAC-AH (from COEM audio in Australia). It all works wonderfully except for one application.

 

I also run eyeTV and here in Australia, at least, HD broadcasts have AC3 (5 channel?) sound associated with them. The DAC doesn't seem to like this! I get pulsed static. When I ran the sound through USB (with a devilsound DAC I had on trial) this was not a problem. Either the devilsound can handle AC3 or it was not outputted as such via USB - I don't know.

 

In Audio Midi setup, it looks like I am setting it for 2 channel stereo output. This doesn't seem to help.

 

Any clues about what I need to do?

 

thanks,

Stan

 

[I. G.]

That's what I've found:

 

For AC3 passthrough, open /Applications/Utilities/Terminal.app and type

 

defaults write com.cod3r.a52codec attemptPassthrough 1

 

To turn off AC3 passthrough, you type this instead:

 

defaults delete com.cod3r.a52codec attemptPassthrough

 

[srobert]

Thanks I.G.,

I tried this but it didn't work. When I tried the second command it told me that this default did not exist. So I tried the first one (same bad sound ) followed by the second one (same bad sound).

 

Any other clues?

 

Stan

 

[srobert]

This has now been solved and I feel stupid. It was a simple preference setting in eyeTV that, I think, seems paradoxical.

 

You must select "system sound output" rather than "digital output" (even though both are outputted digitally in my case via toslink to my DAC) if you want 2 channel stereo.