I have a friend using 6sn7tubes in the amp input and they are 15 years old. Working well, no noise or problems. Use until noise is an issue. Life ends with noise for me. Jallen
Tube Life
I’m using a phono pre-amp with a pair of telefunken 12AX7 and one 12AT7. I purchased these tubes several years ago and they were rated at about 50% life. Are tube noise and tube rush the only reasons to change out tubes? Everything is silent and yet I can’t help but think that several years of use should indicate some sort of wear. Any experience or suggestions will be appreciated.