A friend gave me a pair of "new" Russian 6N3C Tubes. According to him, these are supposed to be the Russian equivalent to the 6L6GC family of tubes. He bought them online, but was unsure about using them, so he gave them to me. I looked online to see what information is out there on these, and have found mixed feelings/messages about these. Anyone out here have or had any experience with these tubes? I refuse to use them until I know more and can be sure they're safe to use in an amp.