Good choice. NEMs are different, built differently, with different materials, probably with cosmic radiation. In Novosibirsk, Igor had the idea: "Boss, for a 300B, a 120-core EL is enough. Oh, nonsense, use the 170-core EL. People want to hear real bass."I will be getting the 300B integrated amp later this week for an incredibly good price...perfect for my second system...if I can get it up into the room (it might be the heaviest 300B amp in existence at 64KG!).