The question about the xlr vs the rca jacks — digital vs. analog — was actually answered in my first post. However, I have to say that it is not beyond me to make that kind of mistake, so I appreciate the effort to eliminate the obvious issues first. That just wasn’t the case this time.
The solution turned out to be Harley’s suggestion: Switch ends on the cable from the K-Box to the Kona 3 card. Seemed an unexpected solution, given that the cable isn’t marked as to which end goes to which unit, but it solved it. Everything works now, and sound is actually coming out of those funny little red and white round things on the lower right hand side of the box. Now, perhaps if I plug these odd, pointy-looking cables into them I can make it louder.
Many thanks for your concern and help,
Mike