I'm sorry, but I'm not clear on what you did.
Are you saying you disconnected the center speaker and connected it to another amp and it sounds okay?
Thanks!
I think what he is saying is that he first tried his setup (including the center) with an outdated Sony receiver, and even though the ear pain problem was not there with the Sony, he wants to try it all with another newer midrange price receiver, and wants some recommendations. At least that is how I read his post.
To the OP, I am not as experienced as these guys...but the idea of running just the fronts in a phantom mode and not having a physical center sounds like it might be a good way to go, and it will save you some money too. Maybe put that toward a newer more-capable receiver?