I'm hoping this is a typo or something, but on page 118 of the EX3 Owner's Manual, under Audio Output, it mentions audio channels 3 and 4. Huh? Only two channels on the EX3, right?

Am I missing something here? Is there a magical hidden set of channels available?

(and yes, I'm a total dweeb for RTFM ;-)

Good question, and let's all us dweebs stick together. I skimmed right over this and forgot about it. In my "paper" manual, it's on page 119.

Manual readers unite!

It is also in the EX1 manual.
I was wondering about that too.

I believe they are referring to the headphone output as channels 3 and 4.

I believe that the XDCam EX standard DOES allow for 4 discrete channels of audio, just as Betacam did, even though most cameras and VTRs wouldn't allow you to access the other 2 (the AFM channels were accessible only with 70-series VTRs, I believe). I'm not sure what in the Sony arsenal allows recording to the OTHER 2 channels, but I do believe they are there, at least from what I remember from speaking to the Sony rep on his XDCam Roadshow about a year ago.