I couldn't -- for the life of me -- get any sound to come through my new UltraLite on Audio Ins 3 and 4. I tried "everything". Hours I worked on this. I posted the question here. I pulled my hair out.... chewed my nails to the quick...
Then, while putting my daughter to sleep, it hit me.
What I thought was plugged into Audio Ins 3 and 4 was actually plugged into Audio Out 3 and 4.
Wow.
I'm an idiot. Just thought I'd share.

cp