Genelex KT-66 v Chinese KT-66 Retros

Hi I actually own some of each. The Chinese tubes sound fine, and I am hard pressed to hear the difference if there is one. I use Quad amps. The build quality and long-term reliability scare me, though. A friend had Chinese EL 34's in his Dyna ST 70 and one shorted with no warning and took out some resistors.My tehnician , who has been servicing tube equipment since the 60's, said that this occurance is rather common with Chinese tubes. John

Thanks for your advice, John. Were the Chinese EL34's early production or Chinese tubes from a while back? I've heard that more recently the Chinese tube quality control has improved. Thanks again. Bill