It is possible to switch between the Infinity and the empeg, at least in theory. SInce you have an amp you can use the empeg as the main hu and then set up the infinity as an aux in. All you have to do is buy a couple of cable ends and do a quick soldering job... I can't find where I those links went, but I will.

While writing this I realized that I am stupid. I just realized the whole six disc spacing problem. That's what I get for cutting down on my coffee intake.