Gold Lion AX7 in tube preamp

Bought a set of these for my tube preamp thinking it might be a nice upgrade. It’s not. They seem to have very high gain and the frequency response is just bad. Vocals are very forward and if you turn things up it gets pretty piercing. I was thinking this would be a warmish preamp tube. What is the break in time and does it really make much difference? They probably have about 40-50 hours of preamp on time. I put the old Tungsols back in and all is good again.