Set up new HK 3490 stereo amp, without too much trouble.Connected 2 Polk tsi 400s and 2 Klipsch KW-100 Subs. Started listening at a low level to warm up amp. As soon as I raised the volume ( not a lot). The amp shut down on a protection fault. Tried running each sub alone, tried no subs, checked all connections for second time. Still could not raise volume without amp protection fault. The tsi 400 fronts have 2 sets of binding posts, I had my entry level Pioneer 5.1 sur. connected to lower posts and HK 3490 Connected to upper posts. Removed pioneer wires from lower connections.l Leaving only HK 3490 Connected to speaker.This worked,amp came alive. What caused this fault,and can it be prevented so both devices can be left connected to speakers. Thanks.