I have an Harmon Kardon PA5800 5 cha. amp and its been working like a underrated champ for 3 yrs or so. Just got a new center channel (Linn 5120) to match some fronts by Linn and my center channel connection is not working. Could I have fried something by connecting a 4ohm speaker to it? Funny thing is, all my other channels are working normally connected to 4 ohm speakers too! I have tried bi-wire only butno response..i tried to connect it to one of the other channels and it works so my wiring is good. I'm frustrated because I have been doing w/o a center for a while and now this? I was using the phantom mode on my preamp now it looks like I have to go back to that... can anyone give me some insight..is it testable (bad channel)? Why would all the other ch. work and not the center when this amp is a 5 channel driven by the same power supply? thanks alot!