My amp is a Music Reference RM-200 which came with RAM KT-88's which were very good, but I too, wanted to do some tube rolling to experiment with the tonal differences that other brands had to offer. I've since tried Shuguang, and Sovtek. Then from reading different forums the name Goden Lions from Genalex kept popping up, all positive. It's been about 3 years since they've been in my system and I haven't had the desire to swap them out for anything else. Warm and revealing are just a few words to describe what they deliver to my ML Aerius. Of course everyone hears differently, but I'm putting up a strong vote,as well, for the Genalex.