Hi all, I have a LM 518ia, too. It's really a great amp. Besides tube rolling, has anyone tried replacing the stock capacitors with audio grade capacitors like Mundorfs, Jantsens...etc? I have tested mine with the Jantsen Z Superiors and Audyn True Copper Maxes. I find that these caps add great improvement over the stock caps and the improvement is more obvious than tube rolling. I like the Audyns better and now they stay in my amp. I just thought I had to share my experience for those who like to try. Happy listening!