Posted this in another thread, but think a new one is merited. I bought 8 of these Russian 6P3-Es tubes in recent months from eBay seller basa_79. Never installed them in an amp. Got a tube tester recently and tested all 8. Five were closely matched in GM. Three of them were bad......I could see the wire windings glowly very brightly on two of them and the meter went wild on my tester. One was just dead. I think all three of the bad ones came in the 2nd purchase and were in the original paper tubes. The first quad purchased had no paper tubes. Buyer beware with this eBay seller. I've contacted him about the problem, will share the results.