Has anyone found a good sound using 12AT7s in place of the 12AX7 input tubes? I have limited good 12AX7s (besides being stupid overpriced now) but more darn good 12AT7s than I know what to do with. Has anyone found any good 12ats in place of the axs? My pre has plenty of drive but I am wondering if the 12AT as an input is proper to drive the second set of 12AT drivers. 5751s never sounded great to me but I am having a bit of luck with the 12ATs