I'm a recent convert to Gold Lion KT77s having used all the other KTs...GL and Sovtek 88s, 120s, 150s, all sounding great in my old Jolida (and all used at some point my current amp), but in the little Dennis Had "SEP" amp I now use the GL 77s are amazingly good and are staying in there. I tried a pair of JJ KT77s and they sucked, but the Gold Lions are utterly different and stellar.