TESLA E88CC 6922 Tubes shorting out???


Hi everyone , I bought quite a bit of Tesla E88CC Tubes white pin. I have tested all of them on my tubes tester, for shorts and for life, they test extremely well. In my ARC ref 1 they sound magnificent, they are so natural it's incredible. The tubes seem to like my ARC Ref 1, no issues with them. As soon as I put them in my amp ARC VT130 SE, in the input stage they seem to last no longer than 20 minutes before you start to hear popping and the channel dies out. So I remove them and install 6H23P-eb and everything is fine again. I then test the removed Tesla on my tester and one of the tubes has shorted out????
Does any one know what's going on ? It has happened twice now..............

Thanks
slates
Thanks Newbee, No these tubes are from the early 90's, they are not JJ
tubes. These tubes are not rugged at all, but they sure sound nice. I'm not putting any in the amp any more. Maybe in the summer I will have it tested
to see if in fact the filament is 6.3 Volts??.

Thanks
Interesting, I went thru a bunch of low noise Tesla's from the early 90's w/out any pre-mature failures except when I used them in my SP10. I have since (the SP10) used them primarily in amps and they were not stressed. All were new stock and I still have some. Your bad luck perhaps. :-(
Newbee, they work great in my ARC ref 1 they don't get along with the ARC VT 130 SE. I think they don't like higher voltage............
Hi Slates: You might want to give the JJ Tesla 7DJ8s a try. I've had no problems, and they sound wonderful in my modded EAR 88PB phono preamp. They even give me more of a spacious, musical sound than original Mullard 6922s which I also have and enjoy, and they're a ton cheaper too.