I don,t know anything about the rogue cronus magnum iii and only a little about tubes but I have recently replaced genalex gold lions both 12AU7 & 12AX7 with Psvane tubes on my pre-amp and the difference was a jaw dropping sound. I paid a small fortune for the gold lions and the Pvanes were were only about $100.00 for 4 tubes. I found the gold lions had a slight glare on the high end and the Psvanes had much better bass and overall a better resolution.