Got this off eBay
Despite the fact that the wiring diagrams for these show 4 wires and a bare ground, mine only has 2 wires and a ground. The spot where the red wire would go has never been connected?!? Am I correct in assuming this is some sort of OEM Classic Stack Plus that is not splittable? If so, that's fairly annoying. I was assuming they were all the same. Doh!