"I am using a Coda CSi Integrated amp that has a pushed bias of 45w class A to about 600 watts 4ohm rating."Good question!
Can somebody tell me what this means?"
It probably means that said amplifier circuit is designed ("biased") so that the first 45W output are in class A; furthermore, the total rated output of the amp is 600W for 4ohms and probably 300W into 8 ohms.